Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A. The name comes from the fact that the oxides of these metals produced basic solutions when dissolved in water, and they remained solids at the temperatures available to the ancient alchemists. Like the Group 1A elements, the alkaline earth metals are too reactive to be found in nature in their elemental form.
The alkaline earth metals have two valence electrons in their highest-energy orbitals (ns2). They are smaller than the alkali metals of the same period, and therefore have higher ionization energies. In most cases, the alkaline earth metals are ionized to form a 2+ charge.
The alkaline earth metals have much higher melting points than the alkali metals: beryllium melts at 1287ºC, magnesium at 649ºC, calcium at 839ºC, strontium at 768ºC, barium at 727ºC, and radium at 700ºC. They are harder metals than the Group 1A elements, but are soft and lightweight compared to many of the transition metals.
Salts of the Group 2A metals are less soluble in water than those of Group 1A because of the higher charge densities on the 2+ cations; nevertheless, many Group 2A salts are at least moderately soluble. Some Group 2A salts bond strongly to water molecules, and crystallize as hydrates; among these are Epsom salt, MgSO4·7H2O, and gypsum, CaSO4·2H2O.
Explanation:
Answer:
H2, N2, O2, F2, Cl2, Br2, I2
Explanation:
The 7 diatomic elements in the periodic table are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine.
Why do elements in the same group have similar physical and chemical properties
Answer:
Each element within a group has similar physical or chemical properties because of its atom's outermost electron shell (most chemical properties are dominated by the orbital location of the outermost electron).
Explanation:
What type of reaction is shown below? Check all that apply. 2Na Cl2 → 2NaCl synthesis decomposition combustion.
Answer:
Synthesis
Explanation:
Trust me on this :)
The burning of fossil fuels contributes to the addition of greenhouse gases to the atmosphere. These gases trap thermal energy in the Earth’s atmosphere. Which of the following would be the most reasonable changes that could result from an increase in the burning of fossil fuels?
Explanation:
The burning of fossil fuels contributes to the addition of greenhouse gases to the atmosphere. These gases trap thermal energy in the Earth's atmosphere.
The materials which contain hydrocarbons which are generated from the remains of decay of plants and animals that are buried underground for many years are called fossil fuels.
What causes by burning fossil fuels?The burning of fossil fuels can affect the environment, climatic conditions and human health. The burning of fossil fuels produces large amount of green house gases like CO₂, CH₄, etc. The increase in the amount of green house gases increases the heat and temperature of the earth's surface which leads to global warming.
The increase of temperature due to global warming can cause rise in the sea level, the glaciers of the earth will melt and coastal areas will be submerged under water due to this.
The burning of fossil fuels also releases toxic gases like SO₂, NO₂ which can cause acid rain and the emission these gases causes air pollution.
Thus the burning of fossil fuels has adverse effects.
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0.0200 moles of a compound is found to have a mass of 1.64 g. Find the formula mass of the compound
Give your answers to 3 significant figures
Answer: 82.0 g/mole
Explanation:
Use the units to see that if we divide 1.64 grams by 0.0200 moles, we'll get a number that is grams/mole, the definition of formula mass.
1.64/0.0200 = 82.0 g/mole (3 sig figs)
We can't tell from this alone what the molecular formula might be, but C6H10 (cyclohexene) comes close (82.1 grams/mole).
The formula mass of the compound will be approximately 82.0 g/mol
The formula mass of the compound is the sum of atomic masses of all the atoms in its chemical formula. It is calculated by adding up the atomic masses of the individual elements in the compound, each multiplied by the subscript indicating the number of atoms of that element in the formula.
To find the formula mass of the compound, we'll use the relationship between moles, mass, and molar mass.
Molar mass (in g/mol) = Mass (in g)/Moles
Given:
Mass = 1.64 g
Moles = 0.0200 moles
Let's plug the values and calculate molar mass:
Molar mass = 1.64 g / 0.0200 moles
Molar mass ≈ 82.0 g/mol
The formula mass of the compound is approximately 82.0 g/mol, rounded to three significant figures.
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Oxygen and Oxygen Ionic or Covalent? Defense how do you know
Answer:
oxygen are covalent bonds because they require 2 more electrons to obtain their octet shell
so when they combine with any other element, they form a covalent bond
Explanation:
Oxygen requires two shared electrons to fill its outermost shell therefore to covalent bonds form.
Consider the Sy2 reaction between 1-bromo-2-methylpropane and methoxide. Add curved arrows to the starting materials to
indicate the flow of electrons. Draw the product species to show the balanced equation, including nonbonding electrons and
formal charges.
H2
Н.С.
Br:
-CH3
product
n Shot
07.42 PI
H
+
CH3
n Shot
.07.13 P1
Draw curved arrows.
Draw the products. The bromide ion has been drawn
for you.
Draw
Select
Rings
More
Erase
Question"
Select
Draw
Rings
More
Erase
h Shot
10.36 PI
///
С
Br
O
С
Br
o
n Shot
-2
Answer:
sdfs
Explanation:
dfssdf
When 1-bromo-2-methylpropane is reacted with methoxide the same product 1-methylprop-2-ene is obtained. This reaction is attached in image below:
What is SN₂ reaction ?The SN2 reaction is a nucleophilic substitution reaction that breaks one bond while forming another. The rate-determining step of the reaction involves two reacting species. SN2 is an abbreviation for Substitution Nucleophilic Bimolecular.
The reaction is bimolecular because two molecules are present in the transition state, as indicated by the number 2 in the SN2 symbol. As a result, the rate of the reaction is affected by the concentrations of both the nucleophile and the substrate.
The SN2 reaction is a nucleophilic substitution with two components in the rate determining step. -SN2 reactions are bimolecular, with bond-forming and bond-breaking steps occurring simultaneously. There is no intermediate in -SN2 reactions.
Thus, product 1-methylprop-2-ene is obtained.
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Which term describes the process that continually moves water from the ground to the atmosphere and back? ASAP
A Evaporation cycle
B Humidity cycle
C Transpiration cycle
D Water cycle
Which polymer structure should be used if a strong and heat - resistant adhesive is required?
1. Linear
2. Branched
3. Networked
4 . Cross - linked
Cross-linked polymers are strong and heat - resistant hence they can be used for this purpose.
A polymer is obtained by the combination of small molecules called monomers. A polymer consists of a regular repeating unit of small molecules called monomers.
A cross-linked polymer is a polymer in which covalent bonds are used to join polymer chains together. Cross-linked polymers are strong and heat - resistant hence they can be used for this purpose.
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renal calculi contain crystallized calcium, magnesium, and uric acid. explain why patients with hyperparathyroidism would be at risk for developing renal calculi.
Patients with hyperparathyroidism would be at risk for developing renal calculi because of high calcium levels excreted by the kidney.
Hyperparathyroidism occurs when there is over secretion of parathyroid hormone by the parathyroid glands.
The parathyroid hormone is responsible for the following in the body:
Release of calcium by bones into the bloodstream. Absorption of calcium from food by the intestines, and Conservation of calcium by the kidneys.Renal calculi are strong masses of stones deposited in the kidneys or urinary bladder.
When there is excess calcium in the blood due to hyperparathyroidism, the kidneys would be over burdened with the excretion of excess calcium.
That extra calcium in the kidney & the urine leads to kidney stone development ( renal calculi).
Therefore, patients with hyperparathyroidism would be at risk for developing renal calculi because of high calcium levels excreted by the kidney.
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T’Keyah puts salt in ice water and then in boiling water to see which will dissolve faster.Which dissolving rate factor is she testing in these tests?
Answer:
temperature
Explanation:
its in the book
Answer: agitation
Explanation:
what chemical properties does soap have that makes it a good cleaning agent?
Answer:
Soap is an excellent cleanser because of its ability to act as an emulsifying agent. An emulsifier is capable of dispersing one liquid into another immiscible liquid. This means that while oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.
Soap acts as a cleaner because of its ability to act as an emulsifying agent. A soap molecule has a polar head and a nonpolar tail. Soap consists of a carbon chain where one end attracts oil and the other attracts water.
What is the cleaning action of soap?Most of dirt can be described as oily in nature as oil does not dissolve in water. The molecule of soap consists of sodium salts of long-chain carboxylic acids. In soaps, the chain of carbon atoms dissolves in the oil, and the ionic or polar end of the soap molecule dissolves in water.
The soap molecules produce structures known as micelles. In micelles, one end faces the oil droplet, and the other end which is ionic in nature faces outside. Therefore, soap can form an emulsion in water and supports in dissolving the dirt when we wash our clothes.
Soap can be described as a kind of molecule in which both ends have different properties. The hydrophilic end dissolves water and is attracted to it whereas the hydrophobic end is dissolved in hydrocarbons and is water repulsive in nature.
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Which of the following is considered quantitative data?
A. Appearance
B. Smell
C. Temperature
Answer:
Temperature
Explanation:
This is because quantitative data include numerical values for example 10 degrees Celsius. However the others are qualitative data because the research can be described but not with numbers like your appearance is very nice.
Hope this helps :P
Answer:
Quantitative data is the type of data whose value is measured in the form of numbers or counts, with a unique numerical value associated with each data set. Also known as numerical data, quantitative data further describes numeric variables (e.g. How many? How often? How much?)
Explanation:
so its temp
Which option is a key point of cell theory? Cells can repair neighboring cells, but not themselves.Cells can repair neighboring cells, but not themselves. , , Cells are the basic structural unit of all living organisms.Cells are the basic structural unit of all living organisms. , , All cells that make up an organism are similar to each other.All cells that make up an organism are similar to each other. , , Some cells can burn food molecules to release energy, but some cannot.
Answer:
Cells are the basic structural unit of all living organisms.
Explanation:
Hope this helps, but i'm unsure if it would be multiple choice or not.
An electrochemical cell operates because the electrodes in the two half-cells differ in their electrical potential. A metal electrode composed of ______ reducing agent will have a greater electrical potential to push electrons toward the electrode composed of a ______ reducing agent.
A metal electrode composed of strong reducing agent will have a greater
electrical potential to push electrons toward the electrode composed of a
weak reducing agent.
Strong reducing agents are compounds which donates or loses electrons
with a corresponding increase in the oxidation state. Weak reducing agents
can also be referred to as oxidizing agents and they accept the electrons
from the strong reducing agents which results in a reduction in the oxidation
state.
The strong reducing agent has a greater electric potential which aids the
electrons being pushed towards the electrodes with a weak reducing agent.
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How many dozens of silver atoms are in the piece of jewelry?.
Infrared waves travel at a speed of 3.00 x 10^8 m/s. What is the frequency of an infrared wave
that has a vacuum wavelength of 5.5 micrometers?
(1 micrometer= 1x10^-6 m)
O 5.5 X 10^12 Hz
O 5.5 x 10^10 Hz
O 5.5 X 10^11 Hz
O 5.5 X 10^13 Hz
The frequency of the infrared wave at the given speed and wavelength is [tex]5.5 \times 10^{13} \ Hz[/tex].
The given parameters;
speed of the wave, v = 3 x 10⁸ m/swavelength of the wave, λ = 5.5 μmThe frequency of the infrared wave is calculated by using wave equation as shown below;
v = fλ
where;
f is the frequency of the wave[tex]f = \frac{v}{\lambda} \\\\f = \frac{3\times 10^8}{5.5 \times 10^{-6}} \\\\f = 5.5 \times 10^{13} \ Hz[/tex]
Thus, the frequency of the infrared wave at the given speed and wavelength is [tex]5.5 \times 10^{13} \ Hz[/tex].
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mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron. carbon. plastic. glass.
Mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.
What is iron?The chemical element iron has the atomic number 26 and the symbol Fe. It is a metal that is found in group 8 of a periodic table and the first transition series. It makes up a large portion of the planet's outer or inner core and is the most prevalent element on Earth by mass, just ahead of oxygen.
It is the fourth most prevalent element in the crust of the Earth, having been mostly deposited by meteorites inside its metallic state, along with its ores. Iron ores must be processed in kilns or furnaces that may reach 5000 °C (2,730 °F) and higher, which is approximately 500 °C (932 °F) greater than the temperature needed to smelt copper. Mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.
Therefore, mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.
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1. (8.5d) A compound has a formula Mg:(PO.). Which best describes the atoms that make up this compound?
A.
B.
Atom
Magnesium (Mg)
phosphorus (0)
Oxygen (0)
Number
2
1
4
Atom
Magnesium (Mg)
Phosphorus (P)
Oxygen (0)
Number
6
2
8
C.
Atom
Magnesium (M)
Phosphorus (2)
Oxygen (0)
Number
3
4
2
D.
Atom
Magnesium (Mg)
Phosphorus (P)
Oxygen (0)
Number
3
2
8
Answer:(8.5d) A compound has a formula Mg:(PO.). Which best describes the atoms that make up this compound? A. B. Atom Magnesium (Mg) phosphorus (0) Oxygen (0)
Explanation:
about how many bacteria colines will grow in a agar plate with a swab of ginger oil
about 6 to 9 colines
if its from mouth if thats the case
TRUE or FALSE the term “anti-inflammatory” likely means “against inflammation”
Answer:
True
ANTI MEANS AGAINST
Explanation:
Answer please
.............................................................
This is not exactly a answer you can use but this is some information that you can use to find out the answer.
You can usually confirm the charge associate degree particle unremarkably has by the element's position on the periodic table: The alkali metals (the IA elements) lose one negatron to create a ion with a 1+ charge. The alkaline-earth metal metals (IIA elements) lose 2 electrons to create a 2+ ion.
Nonmetals type negative ions (anions). A range 7|chemical element|element|gas} atom should gain 3 electrons to possess an equivalent number of electrons as AN atom of the subsequent gas, neon. Thus, a gas atom can type AN ion with 3 additional electrons than protons and a charge of 3−.
if your going down a hill what type of energy are you making?
Answer:
Gravitational potential energy - into Kinetic energy
Explanation:
What is the theoretical yield of sodium chloride when 8.3 g of sodium is reacted with 4.5 g of chlorine? 2Na(s) + Cl2(g) → 2NaCl(s)
The theoretical yield of sodium chloride when 8.3 g of sodium react with 4.5 g of chlorine is 3.30 g
We'll begin calculating the masses of Na and Cl that reacted and the mass of NaCl produced from the balanced equation.
2Na + Cl₂ —> 2NaClMolar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of Cl₂ = 2 × 35.5 = 71 g/mol
Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g
SUMMARY
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂ to produce 117 g of NaCl
Next, we shall determine the limiting reactant.From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂
Therefore,
8.3 g of Na will react with = (8.3 × 71)/46 = 12.81 g of Cl₂
From the calculation made above, we can see that a higher amount (i.e 12.81 g) of Cl₂ than what was given (i.e 4.5 g) is needed to react completely with 8.3 g of Na.
Therefore, Cl₂ is the limiting reactant and Na is the excess reactant
Finally, we shall determine the theoretical yield of NaCl by using the limiting reactant (i.e Cl₂)From the balanced equation above,
71 g of Cl₂ reacted to produce 117 g of NaCl.
Therefore,
4.5 g of Cl₂ will react to produce = (4.5 × 117)/71 = 3.30 g of NaCl
Thus, the theoretical yield of NaCl produced is 3.30 g
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Answer:
The correct answer is 7.4 g NaCl
Explanation:
How often a wave occurs is the wave’s
A. crest.
B. frequency.
C. wavelength.
D. amplitude
Frequency – The frequency of a wave is the number of waves that pass a given point in a certain amount of time. Frequency is measured in units called hertz (Hz), and is defined as the number of waves per second. A wave that occurs every second has a frequency of 1 wave per second (1/s) or 1 Hz.
How many deciseconds are
in 554 seconds?
Give your answer in standard form.
Answer:
5540
Explanation:
Answer:
5,440
Explanation:
10 deciseconds = 1 seconds
554 seconds = 5,440 seconds
What is an ionic bond.
Answer:
ionic bond is the type of bond formed from electrostatic attraction between oppositely charged ion in a chemical compound
(Please someone help me!) (No links!)
Match the following motions to these graphs:
Answer:
Speeding up: graph 6
Slowing down: graph 1
Fast Constant Speed, forward: graph 2
Slow constant speed, forward: graph 5
Fast constant speed, Backward: graph 4
Slow constant speed, Backward: graph 7
Sitting still: graph 3
(Im not 100% but this makes the most sense i think)
I NEED THE ANSWER ASAP! Its science btw
Which statement describes conditions in which a mineral can form?
A. Crystals of minerals dissolve in the groundwater in caves.
B. Materials dissolved in seawater crystallize on an ocean bottom.
C. Molten materials are cooled in a netalworks factory
D. Materials are mined from deposits deep underground.
Answer:
b
Explanation:
ΕΛΑ
1
a
C
Copper(II) nitrate decomposes on heating. The reaction is endothermic.
2Cu(NO),(s) → 2CuO(s) + 4NO2(g) + 0,(9)
Sketch a reaction pathway diagram for this reaction to include the
activation energy
[3]
b Draw an energy cycle to calculate the standard enthalpy change for
this reaction, using enthalpy changes of formation.
[3]
Calculate the enthalpy change for this reaction using the following
enthalpy changes of formation.
AH, [Cu(NO, ),(s)] = -302.9 kJ mol-'
AH, [CuO(s)] =-157.3 kJ mol-!
AH [NO,(g)] = +33.2 kJ mol-!
[3]
d Copper(II) sulfate is soluble in water. A student dissolved 25.0 g of
copper(II) sulfate in 100 cm of water in a polystyrene beaker stirring
all the time. The temperature of the water fell by 2.9 °C.
i Calculate the enthalpy change of solution of copper(II) sulfate.
(specific heat capacity of water = 4.18 Jg1 °C ; relative
molecular mass of copper(II) sulfate = 249.7 g mol-')
[3]
ii Suggest one source of error in this experiment and explain how
the error affects the results.
[2]
[Total: 14]
This problem provides information about the decomposition of copper(II) nitrate to copper(II) oxide and dinitrogen monoxide; for example, it is endothermic, the enthalpies of formation and the chemical reaction, as well as copper (II) sulfate which when dissolved in water, exhibits a temperature decrease:
[tex]2Cu(NO_3)_2(s) \rightarrow 2CuO(s) + 4NO_2(g) + O_2(g)[/tex]
First of all, we can draw the reaction pathway as shown on the attached figure, by taking into account the positive enthalpy change as it is endothermic, so that the products turn out with higher energy than the reactants, for it to be positive. In addition, keep in mind that top point is the activation energy the reaction needs to take place.
Next, we calculate the enthalpy change for this reaction by using the general formula which subtracts the enthalpy of formation of products and reactants with each species' correct stoichiometric coefficient:
[tex]\Delta H=2\Delta _fH_{CuO}+4\Delta _fH_{NO_2}+\Delta _fH_{O_2}-2\Delta _fH_{Cu(NO_3)_2}[/tex]
So we plug in the given enthalpies of formation:
[tex]\Delta H=2(-157.3)+4(33.2)+(0)-2(-302.9)=424.0 kJ/mol[/tex]
Finally, we go over the calorimetry experiment, whereby the total heat absorbed by the copper(II) sulfate is calculated via the general heat equation, which includes the heat loss from the solution of water and the salt:
[tex]Q_{rxn}=-mC_w\Delta T\\\\Q_{rxn}=-(100+25)g*4.18\frac{J}{g\°C}*-2.9\°C=1515.25J[/tex]
By dividing the previous answer by the moles of salt:
[tex]n=25.0g*\frac{1mol}{249.7g}=0.100mol[/tex]
We can obtain the enthalpy change of solution of the copper salt:
[tex]\Delta _{dissolution}H=\frac{1,515.25J}{0.100mol} \\\\\Delta _{dissolution}H=15,134J/mol=15.1kJ/mol[/tex]
To conclude, it is important to note that one possible source of error is we are assuming the solution has the same specific heat to that of water and that is not necessarily true. Also, we are neglecting any heat transfer to and from the surroundings despite the polystyrene beaker is considered a heat isolator, which means the results cannot necesarilly be accurate and the enthalpy change could have turned out higher or lower in a rigoruous experiment.
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https://brainly.com/question/15862043https://brainly.com/question/11667877What is the name of the zone of life on earth ?
a . atmosphere
b . biosphere
c . lithosphere
d . magnetosphere
Answer:
B. Biosphere
Explanation:
