Which of the following is the best definition of a physical change?

A. Ice melting into water.
B. A change that occurs without changing the identity of the substance.
C. Something that can be observed or measured while changing the identity of the substance.
D. A nail rusting.

Answers

Answer 1
You’re best choice is B

Related Questions

According to an informal 1992 survey, the drinking water in about one-third of the homes in Chicago had lead levels of about 10 ppb. Dr. Koether lived in Chicago from 1996 to 1998. Assuming she drank 1.4 L of water a day, calculate the total amount of lead in mg (using one decimal place) that she was exposed to over the two years if she lived in a home that had such high levels of lead.

Answers

Answer:

10.2 mg

Explanation:

Step 1: Calculate the total amount of water she drank

1 year has 365 days and she lived in Chicago for 2 years = 2 × 365 days = 730 days.

If she drank 1.4 L of water per day, the total amount of water she drank is:

730 day × 1.4 L/day = 1022 L

Step 2: Calculate the amount of Pb in 1022 L of water

The concentration of Pb is 10 ppb (10 μg/L).

1022 L × 10 μg/L = 10220 μg

Step 3: Convert 10220 μg to milligrams

We will use the conversion factor 1 mg = 1000 μg.

10220 μg × 1 mg/1000 μg = 10.2 mg

When a chemical changes from the solid phase to the gas phase, this is an example of What chemical property?

Answers

Answer:

sublimation

Explanation:

solid => liquid   Melting

liquid => solid   freezing

liquid => gas     evaporation

gas => liquid     condensation

solid => gas      sublimation

gas => solid      deposition (e.g.; formation of frost), however some scholars will also refer to this process as sublimation.

Rewrite this measurement with a simpler unit, if possible.
4.5·m2m2m

Answers

Answer:

why are people s opinions and prejudices her greatest obstacles

Explain why it is not advisable to add water to acid when
mixing them​

Answers

Answer:

Consequence

you form an extremely concentrated solution of acid initially.and the solution may boil very violently, splashing concentrated acid.  I hope this helped! :)

Which of the following stays constant when diluting a solution?

Select the correct answer below:

A) volume
B) molarity
C) concentration
D) amount of solute

Answers

Answer:

when you're diluting a solution, you're adding in more solvent, so the solute will maintain the same (D)

In water, a substance that ionizes completely in solution is called a

Answers

Answer:

please mark me brainliest

Explanation:

In water, a substance that ionizes completely in solution is called a weak electrolyte.

Answer: strong electrolyte.

Explanation: In water, a substance that ionizes completely in solution is called a. a. weak electrolyte.

An object with a mass of 3kg has a force of 9 newtons applied to it. What
is the resulting acceleration of the object?

Answers

Answer:

3 m/s^2

Explanation:

m = 3 kg

F = 9 N

Use Newton's Second Law: F = ma

9 = 3a

a = 3 m/s^2

The correct geometry around oxygen in CH3OCH3 is
(a). linear. (b). bent. C). tetrahedral/(a). trigonal planar​

Answers

Explanation:

the force of the lone pairs from the bottom would cancel out the force of the lone pairs from the top. Thus, the molecule will be linear.

a team of engineers has decided to design a new shoe for people suffering from a painful foot condition. What should the engineers do during the planning stage

Answers

team of engineers has decided to design a new shoe for people suffering from a painful foot condition. What should the engineers do during the planning stage

A functional group introduces heteroatoms into a carbon chain to increase





polarity.




chain length.




molecular mass.




reactivity.

Answers

Answer:

reactivaty

Explanation:

here you go for the answer

Over a long period of time the process of deposition causes the formation of
O
A. acid rain
OB. glaciers
OC. sedimentary rock
OD. Karst topography

Answers

Answer:

C. sedimentary rock

Explanation:

Deposition is basically a process in which sediments are added to land.

The answer would be option 0C. Sedimentary rock
Hope this helped

What is the balanced equation for the reaction of lithium metal with fluorine gas? Li ( s ) + F ( g ) → LiF ( s ) Li ( s ) + F 2 ( g ) → LiF ( s ) 2 Li ( s ) + F 2 ( g ) → 2 LiF ( s ) Li ( s ) + F 2 ( g ) → LiF

Answers

Answer:

2Li(s) + F2(g)→2LiF(s)

Explanation:

A 1 L container originally holds 0.4 mol of N2, 0.1 mol of O2, and 0.08 mole of NO. If the volume of the container holding the equilibrium mixture of N2, O2, and NO is decreased to 0.5 L without changing the quantities of the gases present, how will their concentrations change

Answers

Answer:

a)  [tex]N_2=0.8mol/L[/tex]

b)  [tex]O_2=0.2mol/L[/tex]

c)  [tex]NO=0.16mol/L[/tex]

Explanation:

From the question we are told that:

Moles 0f Nitrogen [tex]N_2=0.4[/tex]

Moles 0f Oxygen [tex]O_2=0.1[/tex]

Volume Decrease [tex]V_2=0.5L[/tex]

Generally, the equation for Concentration is mathematically given by

[tex]C=\frac{moles}{V}[/tex]

For Nitrogen

[tex]N_2=\frac{0.4}{0.5}[/tex]

[tex]N_2=0.8mol/L[/tex]

For Oxygen

[tex]O_2=\frac{0.1}{0.5}[/tex]

[tex]O_2=0.2mol/L[/tex]

For Nitrogen

[tex]NO=\frac{0.08}{0.5}[/tex]

[tex]NO=0.16mol/L[/tex]

Which molecule is butane?

Answers

Answer:

option c see image... and yw

The molecule shown in option C is butane.

What is butane?The organic compound with four carbon atoms and ten hydrogen atom lie in linear chain without any functional group is called butane.It is belongs to alkane family.

What is alkane?It is  acyclic saturated hydrocarbons organic compounds.It is also known as paraffin.An alkanes contain carbon atoms and hydrogen atoms bonded with single bond.It general formula is [tex]C_{n} H_{n+2}[/tex] .

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What particules make up the nucleus

Answers

Answer:

nucleus is a collection of particles called protons,which are positively charged..and neutrons which are electrically neutral..electrons which are negatively charged..and neutrons are in turn made up of particles called quarks ..

Explanation:

hope this helps u ...

Answer:

The Nucleus is made up of protons and neutrons.

HELP ASAP PLS
Reactions, products and leftovers

Answers

Answer:

See the answer below

Explanation:

From the original equation in the image, the mole ratio of C:CO2:CO is 1:1:2. This means that for every 1 mole of C and CO2, 2 moles of CO would be produced.

Now, looking at the simulation below the equation of the reaction, 3 moles of C and 8 moles of CO2 were supplied as input. Applying this to the original equation of reaction, C seems to be a limiting reagent for the reaction because the ratio of C to CO2 should 1:1.

Hence, taking all the 3 moles of C available means that only 3 moles out of the available 8 for CO2 would be needed. 3 moles c and 3 moles CO2 means that 6 moles CO would be produced (remember that the ratio remains 1:1:3 for C, CO2, and CO). This means that 5 moles CO2 would be leftover.

In other words, all the 3 moles C would be consumed, 3 out of 8 moles CO2 would be consumed, and 6 moles CO would be produced while 5 moles CO2 would be leftover.

An analytical chemist is titrating of a solution of hydrazoic acid with a solution of . The of hydrazoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it.

Answers

Answer:

pH = 12.43

Explanation:

...is titrating 212.7 mL of a 0.6800 M solution of hydrazoic acid (HN3) with a 0.2900 M solution of KOH. The p Ka of hydrazoic acid is 4.72. Calculate the pH of the acid solution after the chemist has added 571.6 mL of the KOH solution to it.

To solve this question we need to know that hidrazoic acid reacts with KOH as follows:

HN3 + KOH → KN3 + H2O

Moles KOH:

0.5716L * (0.2900mol /L) =0.1658 moles of KOH

Moles HN3:

0.2127L * (0.6800mol/L) = 0.1446 moles HN3

As the reaction is 1:1, the KOH is in excess. The moles in excess of KOH are:

0.1658 moles - 0.1446 moles =

0.0212 mol KOH

In 212.7mL + 571.6mL = 784.3mL = 0.7843L

The molarity of KOH = [OH-] is:

0.0212 mol KOH / 0.7843L = 0.027M = [OH-]

The pOH is defined as -log [OH-]

pOH = -log 0.027M

pOH = 1.57

pH = 14 - pOH

pH = 12.43

which of the following measurements is equivalent to 5.461x10^-7m?

Answers

Answer:

B. 0.0000005461m

I used the method of moving the decimal.

convert 14.72 kg to ____ mg

Answers

Answer:

14720000

Explanation:

1 kg = 1000000 mg

14.72 kg = 14.72 x 1000000

=14720000

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What functional group is found in an alcohol?
A. Ester
B. Amino
C. Carbonyl
D. Hydroxyl ​

Answers

Answer:

an alcohol is a Hydroxyl group due to the OH~ that is associated with it's molecules

The functional group found in an alcohol is Hydroxyl . Therefore, the correct option is option D.

What is functional group?

A functional group in organic chemistry is a substituent and moiety inside a molecule that triggers the molecule's distinctive chemical processes. No matter how the rest of a molecule is made up, the very same functional group would experience the same or a similar set of chemical events.

This permits the design of synthetic chemistry as well as the methodical forecasting of chemical reactions as well as the behaviour of chemical molecules. Other functional groups close by can affect a functional group's reactivity. Retrosynthetic analysis can be used to design organic synthesis by using functional group interconversion. The functional group found in an alcohol is Hydroxyl .

Therefore, the correct option is option D.

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A sample of gas occupies 10.0 L at 240°C under a pressure of
80.0 kPa. At what temperature would the gas occupy 20.0 L if
we increased the pressure to 107 kPa?

Answers

Answer: 1090°C

Explanation: According to combined gas laws

(P1 × V1) ÷ T1 = (P2 × V2) ÷ T2

where P1 = initial pressure of gas = 80.0 kPa

V1 = initial volume of gas = 10.0 L

T1 = initial temperature of gas = 240 °C = (240 + 273) K = 513 K

P2 = final pressure of gas = 107 kPa

V2 = final volume of gas = 20.0 L

T2 = final temperature of gas

Substituting the values,

(80.0 kPa × 10.0 L) ÷ (513 K) = (107 kPa × 20.0 L) ÷ T2

T2 = 513 K × (107 kPa ÷80.0 kPa) × (20.0 L ÷ 10.0 L)

T2 = 513 K × (1.3375) × (2)

T2 = 1372.275 K

T2 = (1372.275 - 273) °C

T2 = 1099 °C

1090 degree Celsius

hope it helps

what substances will make salt when combined?
vinegar and soda
soda and wine
detergent and ammonia
fertilizer and vinegar

Answers

Answer:

vinegr and soda ..................

........

Answer:

acid + base = salt

so the answer is vinegar and soda

Explanation:

hope it helps you

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What is the correct IUPAC name for Ir(NO₂)₄

Answers

Answer

Iridium(IV)Nitrite

The correct IUPAC name of the Ir(NO₂)₄ compound is Iridium(IV)Nitrite.

What is the IUPAC name?

Whether it's in a continuous chain or just a ring, the largest chain of carbons joined by a single bond serves as the basis for IUPAC nomenclature.

What is a compound?

A chemical compound would seem to be a substance that contains numerous similar molecules made of atoms from different elements joined by chemical bonds.

The given compound is Ir(NO₂)₄. It can be seen that 4 nitro group is attached with Ir and its coordination number is 4. Hence, the IUPAC name will be Iridium(IV)Nitrite.

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Kevin's supervisor, Jill, has asked for an update on today's sales. Jill is pretty busy moving back and forth between different store locations. How can Kevin most effectively deliver an update to her? a) Send a detailed email Send a detailed text message Oc) Book a one-hour meeting for tomorrow morning O d) Call with a quick update

Answers

Kevin can effectively deliver an update by sending a detailed EMAIL to Jill

Email, which means electronic mail is a technological advanced way of passing information from persons to persons without physical contact. Sending emails are also official ways of passing vital information regarding business, work to and fro.

According to this question, Jill is a very busy supervisor who hardly. The best way for Kevin to deliver any update concerning the store he is managing is to send Jill an updated email that can even be assessed outside work hours. Learn more: https://brainly.com/question/7098974

an endothermic reaction is one which A. reacts very fast. B. reacts very slowly. C. absorbs heat energy. D. releases heat energy.​

Answers

Answer:

D. releases heat energy.​

Explanation:

20. Stoichiometry is based on
A. molecular weight.
B. temperature.
C. conservation of matter.
D. pressure.

Answers

Answer:

The correct option is (c)

Answer:

the law of conservation of mass

FORMULAS OF IONIC COMPOUNDS
FIND: POSITIVE ION, NEGATIVE ION AND FORMULA IN:
NAME:
Sodium chloride
Magnesium chloride
Calcium oxide
Lithium phosphide
Aluminum sulfide
Calcium nitride
Iron(III)chloride
Iron(II)oxide
Copper(I)sulfide
Copper(II)nitride
Zinc oxide
Silver sulfide
Potassium carbonate
Sodium nitrate
Calcium bicarbonate
Aluminum hydroxide
Lithium phosphate
Potassium sulfate

Answers

Answer:

NaCl, Na⁺,Cl⁻.

MgCl₂, Mg²⁺, Cl⁻.

CaO, Ca²⁺, O²⁻.

Li₃P, Li⁺, P³⁻.

Al₂S₃, Al³⁺, S²⁻.

Ca₃N₂, Ca²⁺, N³⁻.

FeCl₃, Fe³⁺, Cl⁻.

FeO, Fe²⁺, O²⁻.

Cu₂S, Cu⁺, S²⁻.

Cu₃N₂, Cu²⁺, N³⁻.

ZnO, Zn²⁺, O²⁻.

Ag₂S, Ag⁺, S²⁻.

K₂CO₃, K⁺, CO₃²⁻.

NaNO₃, Na⁺, NO₃⁻.

Ca(HCO₃)₂, Ca²⁺, HCO₃⁻.

Al(OH)₃, Al³⁺,OH⁻.

Li₃PO₄, Li⁺, PO₄³⁻.

K₂SO₄, K⁺, SO₄²⁻.

Explanation:

Sodium chloride. NaCl, formed by the cation Na⁺ and the anion Cl⁻.

Magnesium chloride. MgCl₂, formed by the cation Mg²⁺ and the anion Cl⁻.

Calcium oxide. CaO, formed by the cation Ca²⁺ and the anion O²⁻.

Lithium phosphide. Li₃P, formed by the cation Li⁺ and the anion P³⁻.

Aluminum sulfide. Al₂S₃, formed by the cation Al³⁺ and the anion S²⁻.

Calcium nitride. Ca₃N₂, formed by the cation Ca²⁺ and the anion N³⁻.

Iron(III)chloride. FeCl₃, formed by the cation Fe³⁺ and the anion Cl⁻.

Iron(II)oxide. FeO, formed by the cation Fe²⁺ and the anion O²⁻.

Copper(I)sulfide. Cu₂S, formed by the cation Cu⁺ and the anion S²⁻.

Copper(II)nitride. Cu₃N₂, formed by the cation Cu²⁺ and the anion N³⁻.

Zinc oxide. ZnO, formed by the cation Zn²⁺ and the anion O²⁻.

Silver sulfide. Ag₂S, formed by the cation Ag⁺ and the anion S²⁻.

Potassium carbonate. K₂CO₃, formed by the cation K⁺ and the anion CO₃²⁻.

Sodium nitrate. NaNO₃, formed by the cation Na⁺ and the anion NO₃⁻.

Calcium bicarbonate. Ca(HCO₃)₂, formed by the cation Ca²⁺ and the anion HCO₃⁻.

Aluminum hydroxide. Al(OH)₃, formed by the cation Al³⁺ and the anion OH⁻.

Lithium phosphate. Li₃PO₄, formed by the cation Li⁺ and the anion PO₄³⁻.

Potassium sulfate. K₂SO₄, formed by the cation K⁺ and the anion SO₄²⁻.

How does the number of molecules in one mole of carbon dioxide compare with the number of molecules in one mole of water?
ОА.
There are four times as many molecules in one mole of carbon dioxide as there are in one mole of water.
ОВ.
There are twice as many molecules in one mole of carbon dioxide as there are in one mole of water.
OC
There are three times as many molecules in one mole of carbon dioxide as there are in one mole of water.
OD
There are the same number of molecules in one mole of carbon dioxide as there are in one mole of water.

Answers

Answer:

d

Explanation:

balance equation of aluminium chloride+ hydrogen​

Answers

[tex]\boxed{\sf {AlCl_3\atop Aluminium\:Chloride}+{H_2\atop Hydrogen}\longrightarrow {Al\atop Aluminium}+{HCl\atop Hydrochloric\:acid}}[/tex]

Balanced Equation:-

[tex]\boxed{\sf {2AlCl_3\atop Aluminium\:Chloride}+{3H_2\atop Hydrogen}\longrightarrow {2Al\atop Aluminium}+{6HCl\atop Hydrochloric\:acid}}[/tex]

3. HNO3 + NaHCO3 → NaNO3 + H2O + CO2
4. AgNO3 +CaCl2 → AgCl + Ca(NO3)2
5. 3 H2(g) + N2(g) → 2 NH3(g)
6. 2 H202 → 2 H2O + O2
Write word equation and type of reaction

Answers

Answer:

hydrogen nitrate + sodium hydrochlorate- sodium nitrate+ water + co2 (acid base reaction)

silver nitrate + calcium chloride - silver chloride+ calcium nitrate ( double displacement reaction)

hydrogen + nitrogen - ammonia gas ( simple contact reaction)

hydrogen peroxide - water + oxygen ( single displacement reaction)

Hope it helps :)

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