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3 years ago

In general, how can the periodic trends displayed by elements be explained?

1 answer:

8 0

The elements within a group in the table have similar properties. ... In general, how can the periodic trends displayed by elements be explained? What is the underlying cause of periodic trends? Trends in atomic size, ionization energy, ionic size, and electronegativity can be explained by variations in atomic structure.

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Which effect does an ocean have on the climate?

kari74 [83]

Answer:

A. ocean winds can carry moisture with them and can bring rain and fog over inland areas

Explanation:

It's "A. ocean winds can carry moisture with them and can bring rain and fog over inland areas' for K12 (OHVA to be exact)

4 0

2 years ago

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Which of the following must be true about a reaction if it is only spontaneous at high temperatures?

Anastaziya [24]

1) Answer is: It is endothermic, with both positive enthalpy and entropy changes.

Endothermic reactions (ΔH>0) that increase the entropy of the system (ΔS>0) are spontaneous at high temperatures.

The change in Gibbs free energy (ΔG), at constant temperature and pressure, is: ΔG=ΔH−TΔS.

ΔH is the change in enthalpy.

ΔS is change in entropy.

T is temperature of the system.

When ΔG is negative, a reaction (occurs without the addition of external energy) will be spontaneous (exergonic).

2) Answer is: It is endothermic and heat is added to the system.

There are two types of reaction:

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.

3) Answer is: For every two AB produced, the reaction requires three A.

Balanced chemical reaction: 3A + B → 2AB.

From balanced chemical reaction: n(A) : n(AB) = 3 : 2.

n(A) = 3 · n(AB) ÷ 2.

A and B are reactants and AB is product of balanced chemical reaction.

For every two AB produced, the reaction requires one B.

4) Answer is:

the amount of required activation energy = potential energy of the B - potential energy of the reactants A.

the enthalpy change of the reaction = potential energy of the products C - potential energy of the reactants A.

For all chemical reaction some energy is required and that energy is called activation energy (energy that needs to be absorbed for a chemical reaction to start).

This is endothermic reaction.

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3 years ago

9. Which statement provides evidence that supports the Big Bang Theory?* 2 points

liberstina [14]

The statement the chemical makeup of the universe has changed dramatically provides evidence that supports the Big Bang Theory (Option D).

<h3>What is the Big Bang Theory?</h3>

The Big Bang Theory is a widely accepted theory in physics that states all the universe began with a huge explosion and form then matters expanded in space at the same time that it is cooling.

Therefore, with this data, we can see that the Big Bang Theory states that the chemical composition of the universe associated with hydrogen and helium modified since this explosion.

Learn more about the Big Bang Theory here:

brainly.com/question/1973038

#SPJ1

4 0

11 months ago

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The specific heat capacity of titanium is 0.523j/g c what is the heat capacity of 2.3g of titanium

kodGreya [7K]

Answer:

1.2029 J/g.°C

Explanation:

Given data:

Specific heat capacity of titanium = 0.523 J/g.°C

Specific heat capacity of 2.3 gram of titanium = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

1 g of titanium have 0.523 J/g.°C specific heat capacity

2.3 × 0.523 J/g.°C

1.2029 J/g.°C

8 0

3 years ago

During a chemical reacion, an iron atom beacme the ion Fe+2. what happened to the iron atom?

galben [10]

Answer:

That iron atom is oxidized. It loses two electrons.

Explanation:

Compare the formula of an iron atom and an iron(II) ion:

Iron atom: $\mathrm{Fe}$ ;
Iron(II) ion: $\mathrm{Fe^{2+}}$ .

The superscript $+2$ in the iron(II) ion is the only difference between the two formulas. This superscript indicates a charge of $+2$ on each ion. Atoms and ions contain protons. In many cases, they also contain electrons. Each proton carries a positive charge of $+1$ and each electron carries a charge of $-1$ . Atoms are neutral for they contain an equal number of protons and electrons.

Protons are located at the center of atoms inside the nuclei. They cannot be gained or lost in chemical reactions. However, electrons are outside the nuclei and can be gained or lost. When an atom loses one or more electrons, it will carry more positive charge than negative charge. It will becomes a positive ion. Conversely, when an atom gains one or more electrons, it becomes a negative ion.

An iron atom $\mathrm{Fe}$ will need to lose two electrons to become a positive iron(II) ion $\mathrm{Fe^{2+}}$ with a charge of $+2$ on each ion. That is:

$\rm Fe \to Fe^{2+} + 2\;e^{-}$ .

Oxidation is Losing one or more electrons;
Reduction is Gaining one or more electrons.

This definition can be written as the acronym OILRIG. (Khan Academy.)

In this case, each iron atom loses two electrons. Therefore the iron atoms here are oxidized.

6 0

3 years ago