For sig figs, you count the total number of numbers that aren’t 0, you only count 0 if they are after a decimal point. since there is not a decimal point, there are 2 significant figures, answer A
The anion<span> is also </span>larger than<span> the </span>atom<span> because of </span>electron-electron repulsion<span>. As more </span>electrons are<span> added to the </span>outer shell<span>, and even to </span>higher<span> principle energy levels, the </span>repulsion<span> bewteen the negatively charged particles grows, pushing the </span>shells<span> farther from the nucleus.</span>
For the reactants,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +5
- The oxidation number of carbon = +3
For the products,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +3
- The oxidation number of carbon = +4
Here, arsenic (+5 to +3) and carbon (+3 to +4) are the only oxidation numbers changing.
Note that an increase in oxidation number means electrons are lost. Thus oxidation is occurring, and a decrease in oxidation number means electrons are being gained, and thus reduction is occurring.
Also, the compound that contains the element being oxidized is the reducing agent, and the compound that contains the element being reduced is the oxidizing agent.
So, the answers are:
name of the element oxidized: Carbon
name of the element reduced: Arsenic
formula of the oxidizing agent: 
formula of the reducing agent: 
Salt dissolved in water is a solution, therefore
- salt is not chemically bonded to water
- the ratio of salt to water may vary
- salt and water retain their own chemical properties
<u>Explanation:</u>
Salt (sodium chloride) is formed from positive sodium ions bonded to negative chloride ions. Water can dissolve salt because the positive part of water particles attracts the negative chloride ions of salt. The water particle effects to be charged negatively near the atom of oxygen and positively near the atom of hydrogen.
Since contrasts attract, the water molecules tend to join collectively like magnets. Water is called the universal solvent since it can solve more substances than any other liquid. The salt and water retain their unique chemical properties.
