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3 years ago

How many valence electrons are in an atom of gold?

1 answer:

3 0

Chemical reactivity of all of the different elements in the periodic table depends on the number of electrons in that last, outermost level, called the valence level or valence shell. In the case of gold, there is only one valence electron in its valence level. Hope I helped! :)

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Write the following numbers in standard notation, maintaining the same number of significant figures.

Alexxandr [17]

Answer:

6.104x10^2=610.4

9.5x10^3=9500

Explanation:

7 0

3 years ago

Which of the following pairs lists a substance that can neutralize H2SO4 and the salt that would be produced from the reaction?

Bogdan [553]

The second option only.

LiOH, Li₂SO₄.

<h3>Explanation</h3>

A base neutralizes an acid when the two reacts to produce water and a salt.

Sulfuric acid H₂SO₄ is the acid here. There are more than one classes of bases that can neutralize H₂SO₄. Among the options, there are:

Metal hydroxides

Ca(OH)₂ and
LiOH.

Metal hydroxides react with sulfuric acid to produce water and the sulfate salt of the metal.

$\text{Ca}(\text{OH})_{\bf 2}+\text{H}_2\text{SO}_4 \to \textbf{Ca}\textbf{SO}_{\bf 4} +{\bf 2}\;\text{H}_2\text{O}$ .

The formula for calcium sulfate $\text{CaSO}_4$ in option A is spelled incorrectly. Why? The charge on each calcium $\text{Ca}^{2+}$ is +2. The charge on each sulfate ion ${\text{SO}_4}^{2-}$ is -2. Unlike $\text{Li}^{+}$ ions, it takes only one $\text{Ca}^{2+}$ ion to balance the charge on each ${\text{SO}_4}^{2-}$ ion. As a result, $\text{Ca}^{2+}$ and ${\text{SO}_4}^{2-}$ ions in calcium sulfate exist on a 1:1 ratio.

$2\;\text{LiOH} +\text{H}_2\text{SO}_4 \to \text{Li}_2\text{SO}_4 + 2\;\text{H}_2\text{O}$ .

Ammonia, NH₃

Ammonia NH₃ can also act as a base and neutralize acids. NH₃ exists as NH₄OH in water:

$\text{NH}_3 + \text{H}_2\text{O} \to \textbf{NH}_{\bf 4}\text{OH}$ .

The ion ${\text{NH}_4}^{+}$ acts like a metal cation. Similarly to the metal hydroxides, NH₃ (or NH₄OH) neutralizes H₂SO₄ to produce water and a salt:

$2\;\textbf{NH}_{\bf 4}\text{OH}+ \text{H}_2\text{SO}_4 \to (\textbf{NH}_{\bf 4})_2\text{SO}_4+2\;\text{H}_2\text{O}$ .

The formula of the salt (NH₄)₂SO₄ in the fourth option spelled the ammonium ion incorrectly.

As part of the salt (NH₄)₂SO₄, the ammonium ion NH₄⁺ is one of the products of this reaction and can't neutralize H₂SO₄ any further.

7 0

3 years ago

In which structure does photosynthesis occur?

zhenek [66]

Answer:

Explanation:

kloroplast

8 0

3 years ago

Read 2 more answers

Which of the following is an example of a compound? CaCl2 Na Nd Cu

madam [21]

CaCl2

All of the other choices are elements

5 0

3 years ago

How would adding the catalyst nitrogen monoxide (NO) affect this reaction?

marin [14]

Answer: The correct answer is Option A.

Explanation:

A catalyst is defined as the substance which increases the rate of the reaction without actually participating in the reaction.

This substance decreases the activation energy of the reactants, so as to proceed the reaction at a faster rate by increasing their effective collisions.

It does not affect the concentration of the reactants.

For the given reaction:

$2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)$

If we add NO, which is acting as a catalyst will increase the rate of the reaction to produce the products which is $SO_3$

Hence, the correct answer is Option A.

5 0

4 years ago

Read 2 more answers