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Which pair of properties describes the elements in Group 18?

F They are chemically stable and liquid at room temperature.

G They have eight valence electrons and are flammable

H They are magnetic and boil at low temperatures.

J They are gaseous at room temperature and chemically stable.

Answers

Answer 1

Answer:

G

Explanation:

They have eight valence electrons and are flammable

*not sure about this answer

Answer 2

Explanation:

the correct answer is C

hope it helps you


Related Questions

What is the name of the molecule shown below?

A) ethanol
B) ethanal
C) ethanoic acid
D) ethylamine

Answers

The answer is B, Ethanal

The name of the molecule shown is Ethanol.

What is Ethanol?

Ethanol is a alcoholic substance that is formed from fermentation of glucose in the presence of yeast or microorganisms.

It has a chemical group that have methyl group, hydroxyl group OH which is bonded to carbon atom.

Therefore, The name of the molecule shown is Ethanol.

Learn more about ethanol below.

https://brainly.com/question/13423304

#SPJ2

plz answer (g) i will give rating 5 and thanks who answer plz fast

Answers

Answer:

Like many common group 2 metal carbonates, magnesium carbonate reacts with aqueous acids to release carbon dioxide and water

 MgCO3 + 2 HCl → MgCl2 + CO2 + H2O.

The procedure to obtain pure magnesium chloride from the reaction is as thus

Step 1: Reaction

- Leave the dilute hydrochloric acid in a beaker.

- Add Magnesium carbonate slowly until it is in excess or until no more gas seem to be getting liberated.

Step 2: Filtration

- Filter with filter paper and funnel.

- Filter off the excess magnesium carbonate as magnesium chloride will be in aqueous form (liquid) and will come out with the filtrate. The residue is the excess magnesium carbonate.

Step 3: Crystallization to obtain solid crystals from the filtrate.

- Pour filtrate solution into evaporating dish/basin

- Provide heat using Bunsen burner

- Pour solution into an evaporating basin and heat over a water bath

- Stop heating when crystals start to form

allow water to evaporate until pure crystals remain.

- Dry crystals using absorbent paper or warm oven.

Precautions

- Use personal protective equipment such as gloves, a lab coat and wear eye protection, especially when heating.

- Avoid inhaling unnecessary gases during the whole process.

8. What is the oxidation number of N in KNO3?

Answers

Answer:

The oxidation state of N in the KNO3 is +5

Explanation:

Oxidation rules:

1. Oxygen is -2, unless in peroxides.

2. Group 1 metals = +1

3. Group 2 metals = +2

4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.

5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.  

So, the given formula represents the salt compound formula unit of potassium nitrate:  KNO3  

The formula unit is uncharged.

From our rules, we know that,

O = -2

And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.

K = +1

N = x

O = -2

Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.

+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)

x - 5 = 0

x = 5

Therefore, the oxidation number of N in KNO3 is +5.

On a plateau on a heating curve, _____.


phase changes are occurring

no heat is being absorbed

all the absorbed heat is being used to overcome forces of attraction between the particles or molecules and phase changes are occurring

all the absorbed heat is being used to overcome forces of attraction between the particles or molecules

Answers

Answer:

On a Plateu on a heating curve phase changes are occuring

Explanation:

The first Phase is melting during which the temrature stays the same while water melts.Other phase changes are freezing sublimation Vaourization condensation and deposition

what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?​

Answers

~Solution :-

Here, we have been given that;

$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 g

Hence, we can note that,

No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$

(n) = 32.05

[tex] \\ [/tex]

Thus,

Molarity = 32.05 mg/L

Hence, molarity of the given solution will be 32.05 mg/L.

Calculate the solubility of Maslog at 25€
4 30-0cm of its Saturated solution at that
temperature gave 180g of the anhydrous
C= 12. 0-46. Ma =23
Salt​

Answers

Answer:

20

Explanation:

calculated saturated solutions

which best describes the relationship between internal energy and thermal energy

Answers

Answer:

answer is d on edge

Explanation:

Can someone answer this ASAP?

Carbon has unique bonding characteristics that allow it to
A
form ionic bonds with any atom to form many different molecules.
B
resist bonding with other atoms and remain a pure element.
С
form chains or rings by bonding to itself and other atoms.
D
form ionic salts that make up half of the known salts on Earth.

Answers

Answer:

С. form chains or rings by bonding to itself and other atoms.

Explanation:

Carbon is an element in group 4 of the periodic table with unique bonding properties. Carbon posseses 4 valence electrons in its outer shell. This enables carbon to form covalent bonds with the atoms of other elements e.g. nitrogen, phosphorus, oxygen, hydrogen etc.

Carbon can also combine covalently with other carbon atoms i.e. C-C to form long chains and rings in a process called CATENATION. This unique property of carbon makes it the only element that can form so many different compounds.

Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is

A.

Answers

Answer:

Explanation:

Formula

The current = charge / time

The charge is in coulombs

The time has to be in seconds.

1 minute = 60 seconds

2 minutes = 120 seconds.

charge = 180 coulombs

current = 180 / 120

current = 1.5 amperes.

A sample of hydrogen gas H2 has a volume of 5.0 L and a pressure of 1.0 atm. What is the final pressure in atmospheres if the volume is decreased to 2 L with no change in temperature and amount of gas

Answers

Answer:

2.5 atm

Explanation:

P = Pressure

V = Volume

P1V1 = P2V2

1 x 5 = P2 x 2

5 = P2 x 2

Divide both sides by 2

5/2 = P2 x 2/2

P2 = 2.5

Hiii please help me for balancing chemical equations:


potassium iodide + chlorine ------> potassium chloride + iodine​

Answers

Answer:

KI + Cl2 = KCl + I2

Explanation:

hope this helps!!!

Answer:

2KI +Cl₂ → 2KCl +I₂

Explanation:

Potassium ion: K+

Iodide ion: I-

Thus, potassium iodide is KI.

Chlorine exist as a diatomic molecule thus it is written as Cl₂.

Chloride ion: Cl-

Thus, potassium chloride is KCl.

Iodine also exist as a diatomic molecule, thus it is written as I₂.

Write an unbalanced equation:

KI +Cl₂ → KCl +I₂

Now balance by ensuring the number of atoms of each element on each side is the same.

LHS

K: 1 ×2= 2

I: 1 ×2= 2

Cl₂: 2

RHS:

K: 1 ×2= 2

I: 2

Cl: 1 ×2= 2

Thus, the balanced equation is:

2KI +Cl₂ → 2KCl +I₂

What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction

Answers

Answer:

B. The amount of produd obtained/amount possible * 100

Explanation:

In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:

Percentage yield = Actual yield/theoretical yield × 100

- The actual yield is the amount of products got from a chemical reaction

- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).

which of the following is an example of an arrthenius acid

Answers

Answer:

The common examples of Arrhenius acid includes HCl (hydrochloric acid), H2SO4 (sulphuric acid), HNO3 (nitric acid), etc.Oct 21, 2020

Explanation:

If we burn 1 gr of ethyl alcohol (C2H5OH) this will translate into a release of about 50 W of thermal energy of the flame that raise the temperature of the hot and cold reservoirs of a Sterling engine at 55 °C and 95 °C respectively. If at steady state the engine turns at about 240 rpm, its gears are shaped as rings of radius ~2 cm and weigh 50 gr, how efficient (in %) is the transfer of energy via flame?

Answers

Answer:

0.116%

Explanation:

efficiency of sterling engine = 1 - ( 55 + 273 )k / ( 95 + 273 ) k

                                               = 1 - ( 328 / 368 ) = 0.10869

Determine how efficient the transfer of energy via flame is

apply this relation ; energy of steady state / energy output  ---- ( 1 )

where;  energy output = efficiency of sterling engine * energy

                                     = 0.10869 * 50 = 5.4345 J/sec

energy of steady state = 1/2 * I * w^2  ------ ( 2 )

I = moment of inertia of engine = 2 * 10^-5 kgm^2

back to equation 2 :  

energy of steady state = 1/2 * ( 2 * 10^-5 ) * ( 240 * 2π / 60 )^2

                                      = 630.88 * 10^-5  J /sec

Input values into equation 1

= [ (630.88 * 10^-5 )  / 5.4345  ] * 100

= 0.116%

Scoring Scheme: 3-3-2-1 Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used

Answers

Answer:

The solution has 0.00994 moles of Co[H2O]6Cl2

Explanation:

Complete question: Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used?

mL= 7.95

Step 1: Data given

Concentration of the starting solution = 1.25 M

Starting solution = Co[H2O]6Cl2

Step 2: Calculate molar mass of Co[H2O]6Cl2

Atomic mass of Co = 58.93 g/mol

Atomic mass of H = 1.01 g/mol

Atomic mass of O = 16.00 g/mol

atomic mass of Cl = 35.45 g/mol

Molar mass of Co[H2O]6Cl2 =

1*58.93 + 12*1.01 + 6*16.00 + 2*35.45 = 237.95 g/mol

Step 3: Calculate number of moles

C = n/v

⇒with C = the Concentration of the starting solution = 1.25 M

⇒with n= the number of moles = to be determined

⇒with v = the volume = 7.95 mL = 0.00795 L

n = C * V

n = 1.25 M * 0.00795 L

n = 0.00994 moles

The solution has 0.00994 moles of Co[H2O]6Cl2

Which of the following changes in the state of a substance results in an increase in the entropy?

Gas to solid
Gas to liquid
Liquid to solid
Solid to liquid

Answers

Answer:

the correct answer is

D. solid to liquid

the correct answer should be D

Which of these hypotheses cannot be tested?
A. The percentage of salt in ocean water stays the same throughout the ocean.
O B. Doubling the amount of salt in a bread recipe will cause the dough to rise faster.
C. Cooks should use sea salt in recipes instead of regular table salt.
O D. Increasing the amount of salt in salt water will increase the boiling point. ​

Answers

Cooks should use sea salt in recipes instead of regular table salt.

neutral radicals examples​

Answers

Neutral radicals are always electropositive

some examples of neutral radicals are:-

C±M±Ba ±±Al±±NH4±

Hope it is helpful to you

write molecular formula
1)aurric cloride
2)aluminium hydroxide
3)potassium thiosulphate
4)magnesium bicarbonate
5)magnesium sulphate
6)sodium oxide
7)cuprous oxide
8)mercuric oxide
9)calcium nitrate
10)aluminium oxide
11)ferric chloride
12)ammoium oxide
13)silver chloride
14)hydrogen bromide
15)magnesium nitride
16)hydrogen peroxide
17)sodium sulphate
18)ammonium sulphate
19)ferrous sulphate
20)sodium carbonate
21)zinc carbonate
22)calcium silicate
23)zinc carbonate
24)potassium clorate
25)aluminium hydroxide
26)ammonium hydroxide
27)sodium silicate​

Answers

Okay.

Here's your below answers.

1) AuCl3.

2) Al(OH)3.

3) K2S2O3.

4) Mg(HCO3)2.

5) MgSO4.

6) Na2O.

7) CuO.

8) HgO.

9) Ca(NO3)2.

10) Al2O3.

11) FeCl2.

12) (NH4)2O.

13) AgCl.

14) HBr.

15) Mg3N2.

16) H2O2.

17) Na2SO4.

18) (NH4)2SO4.

19) FeSO4.

20) Na2CO3.

21) ZnCO3.

22) CaSiO3.

23) ZnCO3.

24) KClO3.

25) Al(OH)3.

26) NH4OH.

27) Na2SiO3.

The graph shows the volume of a gaseous product formed during two trials of a reaction. A diferent concentration of reactant was used during each trial, whereas the other factors were kept constant. Trial 2 Amount of Product Trial 1 Time Which of the following statements explains which trial has a lower concentration of the reactant? O Trial 1, because the average rate of the reaction is lower. O Trial 1, because this reaction lasted for a longer duration than Trial 2. O Trial 2, because this reaction was initially fast and later slowed down. O Trial 2, because the volume of product formed per unit time was higher​

Answers

Answer:

A). Trial 1, because the average rate of the reaction is lower.

Explanation:

The first sentence elaborates that 'trial 1 had a lower level of concentration of the reactant that eventually led the reaction's average rate to fall.'

A trial having a higher level of concentration of a specific reactant will cause the concentration's average rate to rise. As per the graph provided, trial 2's average reaction rate is higher which shows that its concentration is greater and more reactive. However, the opposite happens in trial 1 where the amount of reactant is lesser in the concentration that leads the concentration to possess a lower rate of reaction. Thus, option A is the correct answer.

Jonny Jonny.
Yes papa?
Eating Sugar?
What comes next?
(A) Yes Papa
(B) No Mama
(C) Yes Mama
(D) No Papa

Answers

Answer:

(B) No papa

arafgzhzhsjdjkskbdjzjsj

Answer:

(D) No Papa

Explanation:

is this even chemistry pffttt

CORRECT ANSWER ONLY ND WILL GIVE BRAINLIEST✌
Calculate the mass of nitrogen dioxide gas that would occupy
the same volume as 10g of hydrogen gas at ē same pressure and temperature
(H= 1.0 N = 14.0 O= 16.0) GAS LAWS/MOLES

Answers

Answer:

150g

Explanation:

Assuming they are ideal gases at the same temperature and pressure, equal moles of gasses have equal volume. IN this case, if we have 10g of hydrogen gas, that is 5 moles of H2 gas. That means 5 moles og NO2 will occupy the same volume which is 5*(14.0 + 16.0*2) =  230 g

Electron transition can be likened to moving up and down a ladder. Which of the following statements best describes how an electron transitions in an electron cloud?
A. An electron can only gain or lose energy to move between quantized energy levels.
B. An electron can only gain or lose charge in integers when ions are formed.
C. An electron can only change its mass in quantized amounts when it gains or loses energy.
D. An electron can only change into certain types of particles when it gains or loses charge.​

Answers

Answer:

C. An electron can only change its mass in quantized amounts when it gains or loses energy.

Explanation:

The electron mostly acts in a wave form and shales the orbit and in other worlds the electron transition to  lower energy change its wave shape and sinks less but it does not leap or bounce back anywhere.

What happens if kinetic energy of a gas is lowered

Answers

Answer:

"If you lower the kinetic energy of a gas its temperature will decrease because temperature is a measure of the average kinetic energy of a substance."

Explanation:

it’s temperature will decrease

Explanation: because temperature is a measure of the average kinetic energy and its substance

Which pair of substances would react the
fastest?
a. Copper sheet and concentrated
nitric acid.
b. Copper powder and dilute nitric acid
C. Copper powder and concentrated
nitric acid.​

Answers

Answer:

C. It has the highest rate of reaction. Copper has the highest TSA/V and concentrated nitric acid has huggest num of solute

For a reaction: aA → Products, [A]o -4.3 M, and the first two half-lives are 56 and 28 minutes, respectively. Calculate k (without units). Show Work!

A. 7.7 x 10^-2
B. 4.2 x 10^-3
C. 3.8 x 10^-2
D. 8.3 x 10^-3
E. None of these​

Answers

Answer:

C.[tex]3.8\times 10^{-2}[/tex]

Explanation:

We are given that

Initial concentration, [tex][A]_o=4.3 M[/tex]

First half life, [tex]t_{\frac{1}{2}}=56[/tex]minutes

Second half life, [tex]t'_{\frac{1}{2}}=28[/tex]minutes

We have to find K.

The given reaction is zero order reaction.

We know that for zero order reaction

[tex]t_{\frac{1}{2}}=\frac{[A]_o}{2k}[/tex]

Using the formula

[tex]56=\frac{4.3}{2k}[/tex]

[tex]k=\frac{4.3}{2\times 56}[/tex]

[tex]k=3.8\times 10^{-2}[/tex]

Hence, option C is correct.

Zero-order reactions are the reactions when a surface or a catalyst is required for the reaction to proceed and is saturated by the reactant chemicals. The result of the concentration versus the time plot will be a straight line in a zero-order reaction.

[tex]3.8 \times 10 ^{-2}[/tex] is the value of k.

How to calculate the value of k?

Given,

Initial concentration [tex][A_{0}][/tex] = 4.3 MThe first half-life of the reactant [tex](t \dfrac{1}{2})[/tex] = 56 minutesThe second half-life of the reactant [tex](t \dfrac{1}{2})[/tex]  = 28 minutes

The given reaction in the question is of zero-order and for that, we know that,

[tex]t \dfrac{1}{2} = \dfrac{[A_{0}] }{2\;\rm k}[/tex]

Substituting the values in the equation we get:

[tex]\begin{aligned}56 &= \dfrac{4.3 }{2\; \rm k}\\\\\rm k &= {4.3 }{2 \times 56}\\\\\rm k &= 3.8 \times 10^{ -2}\end{aligned}[/tex]

Therefore, option C is correct.

Learn more about the zero-order reaction here:

https://brainly.com/question/4638382

!!!!!!URGENT!!!!!!
What do the coefficients in the following balanced chemical equation mean?
2H2 + O2 + 2H2O

A) 2 moles of hydrogen and 1 mole of oxygen in the reactants

B) 2 moles of oxygen and 1 mole of hydrogen in the reactants

C) 2 moles of oxygen and 1 mole of hydrogen in the products

D) 2 moles of hydrogen and 1 mole of oxygen in the products

Answers

Answer:

2moles of hydrogen and 1 mole of oxygen in the reactants

What is the name of this compound

Answers

Answer:

horizontal

Explanation:

Which is a mixture?
Sodium metal
chlonne gas
sodium metal and chlonne gas
sodium chlonde (salt) and water

Answers

Answer:

I believe it's salt and water

Explanation:

not sure

Answer:

Mixture is a electronic device used to peel the things such as onion ,tomato,ginger, garlic etc.

TIMED PLS PLS HELP ASAP

The scattering of sunlight by the mixture of gas molecules in air results in the blue color of the sky. Calculate the energy (in Joules) of a single photon of blue light with a frequency of 6.00 × 10¹⁴ Hz. (h = 6.626 × 10⁻³⁴ J • s)

Answers

Answer:

It's me mario

Explanation:

Other Questions
Consider the reaction of 2-chloro-2-methylpentane with sodium iodide.Assuming no other changes, how would it affect the rate if one simultaneously doubled the concentration of 2-chloro-2-methylpentane and sodium iodide?A) No effect.B) It would double the rate.C) It would triple the rate.D) It would quadruple the rate.E) It would increase the rate five times. What is the intent of a Pigouvian tax? A. To encourage producers of a negative externality to increase production to the socially optimal level. B. To eliminate the force of the invisible hand in market transactions. C. To mandate by government fiat the reduction of production to the socially optimal level. D. To induce producers of a negative externality to reduce production to the socially optimal level. Find the width of a rectangular strip of land with length 25 m and area 12 square meters? PLs help T^T im to dum.b to understand this equation Hydrogen gas and fluorine gas will react to form hydrogen fluoride gas. What is the standard free energy change for this reaction In at least 500 words, write a reflective essay on a text or texts you've read that focuses on South Africa. What did you learn and how did the readings change or enlarge your world view? Make sure to reference all of the works you read. How did the work of Dmitri Mendeleev differ from that of John Newlands in the development of the periodic table? Synovec Company is growing quickly. Dividends are expected to grow at a rate of 30 percent for the next three years, with the growth rate falling off to a constant 4 percent thereafter. If the required return is 10 percent, and the company just paid a dividend of $2.65, what is the current share price You have seen this advertisement for a summer job. Summer shop assistants needed for our new arts and crafts shop You need to: be good at working with people . have some knowledge of arts and crafts be able to work during the busy tourist season in July and August Write saying why you would be suitable for the job to: Robert Brown, Manager, The Art of Craft, High Street, Oxford Write your letter. (140-190 words) Which factors have been major influences on the growth of American cities 3rd time. l'll give ya brainliest if you answer. anyway-can someone make this sentence more like a 7th grader said it or something:The West has large open areas untouched by people. The land includes large forests, deserts, and mountains. The variety causes wide differences in weather. Hiking and camping are popular. The environment is an important issue. Ranching, lumbering, and mining are important industries. Los Angeles, Seattle, and Denver are major cities.(please dont say this sounds like a 7th grader, this is in the assigngment and i have to change it in my own words but i dont know how to.) COMPREHENSION 4. Read the following passage carefully and answer the questions which follow. One day, it suddenly dawned on me how my parents were ageing. My father who once was tall and strong was now showing strains on his face through toils on his farm. He was wearing wrinkled face and had grey hair all over his head. Looking at his youthful days pictures, I am much convinced that women sang him praises. My mother, though carried her age much better, had been robbed of her strength, and her breasts emptied through childbearing and breast feeding respectively. However, she still carries on with her petty trading activities as a habit and not necessity.My mother now smiles slowly and rarely speaks. Her face and skin remain smooth and her expression is self-satisfactory. My parents who are now the head of their respective extended family, represent the highest and wisest authority. a. What had caused the strains in the writer's father's face? b. What is the writer convinced about? c. What had robbed of the writer's mother's strength? d.What had emptied the writer's mother's breasts? e. Why does the writer's mother still sell? f. The writer's parents represent ......... in their extended families g. Explain the following expressions in your own words. i. Women sang him praises ii. Still carries on with h. For each of the following words, give another word or phrase that means the same and can fit into the passage. i. Dawned on ii. Robbed of III. Rarelyiv. Authority help pls!!!!! What is the inequality for this verbal description?The value of y is greater than or equal to the sum of five times the value of xand negative three. Daniel and Saquon are each saving money. Daniel starts with $50 in his savings account and adds $8 per week. Saquon starts with $65 in his savings account and adds $5 each week.After four weeks, who has more money in their savings account? Explain how you know.After how many weeks will Daniel and Saquon have the same amount of money in their savings accounts? The accountant for Sysco Company is preparing the company's statement of cash flows for the fiscal year just ended. The following information is available: Retained earnings balance at the beginning of the year $ 819,000 Net income for the year 230,000 Cash dividends declared for the year 42,000 Retained earnings balance at the end of the year 1,007,000 Cash dividends payable at the beginning of the year 10,000 Cash dividends payable at the end of the year 11,000 What is the amount of cash dividends paid that should be reported in the financing section of the statement of cash flows Which individual popularized the idea that people accused of crimes should be considered innocent unless proven guilty What is the area if measurements are 6m x 5.2m A business should choose the platform as a service (PaaS) cloud model when: a. it designs its own applications but doesn't customize the operating system b. it doesn't need any operating system c. it doesn't design its own applications and doesn't customize the operating system d. it designs its own applications and customizes the operating system e. it doesn't design its own applications but customizes the operating syste Ferrero Rocher chocolates are manufactured in the shape of spherical balls, which are wrapped in foil. The Ferrero Rocher Company introduced the Ferrero collection, which is a package of 15 chocolates, one layer deep in a 3 chocolate x 5 chocolate orientation. A single chocolate has a diameter of 3.2 cm. 50 POINTSUse the function f(x) to answer the questions.f(x) = 16x2 + 22x + 3Part A: What are the x-intercepts of the graph of f(x)? Show your work. (2 points)Part B: Is the vertex of the graph of f(x) going to be a maximum or a minimum? What are the coordinates of the vertex? Justify your answers and show your work. (3 points)Part C: What are the steps you would use to graph f(x)? Justify that you can use the answers obtained in Part A and Part B to draw the graph. (5 points)