Electrons occupy shells around the outside of an atom. There can be up to two electrons in the first shell, up to eight in the second and up to eight in the third. A calcium atom (Ca) has electron structure 2,8,8,2.

Correct Option: C

Electrons occupy shells around the outside of an atom. There can be up to two electrons in the first shell, up to eight in the second and up to eight in the third. A calcium atom (Ca) has electron structure 2,8,8,2.

When water combines chemically with other elements, the process is called hydration. In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl group (–OH) and a hydrogen cation (an acidic proton) are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group. The reaction usually runs in a strong acidic, aqueous solution. Hydration leaves the non-water component intact.

Correct Option: C

When water combines chemically with other elements, the process is called hydration. In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl group (–OH) and a hydrogen cation (an acidic proton) are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group. The reaction usually runs in a strong acidic, aqueous solution. Hydration leaves the non-water component intact.

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral. Galena is one of the most abundant and widely distributed sulfide minerals.

Correct Option: A

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral. Galena is one of the most abundant and widely distributed sulfide minerals.

Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. It is a lachrymatory substance.

Correct Option: C

Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. It is a lachrymatory substance.

The chemical behavior of an atom is determined by the number of electrons on its outer shell. As for the chemical bonding properties of the atom, the electron configuration determines how it will bond, with what it will bond, and in what ratio atoms will bond to form the 20,000,000 different substances on Earth.

Correct Option: C

The chemical behavior of an atom is determined by the number of electrons on its outer shell. As for the chemical bonding properties of the atom, the electron configuration determines how it will bond, with what it will bond, and in what ratio atoms will bond to form the 20,000,000 different substances on Earth.