A) Metal has luster
Metals are ductile, malleable, and good conductors of heat.
Answer:
Plastics are large organic molecules called polymers.
Explanation:
Plastics can be defined as materials that can be shaped when soft and then hardened to keep their shape. They are synthetic (artificially made) or semi-synthetic, derived from materials found in nature, such as natural gas, oil, coal, minerals, and plants.
As they are derived from natural, organic materials, plastics also consist of organic molecules. Their molecules are very large and long and consist of many repeating subunits. Materials with this type of structure are called polymers.
This is why the second option is the correct one.
Positive ions are positive because they have lost electrons.
(A)-This sounds accurate, but is actually not true. When an atom loses an electron and forms a positive ion, there will be less negative charge from the electrons to attract the positively charged nucleus. Losing electrons will actually decrease the attraction between the electrons and the nucleus.
(B)-This is true in some cases, but not all. If, for example, sodium were to lose an electron, it would drop down to having its largest orbital being in the second energy level, and would decrease in size. If magnesium were to lose an electron, it would still have one electron in the third energy level, so it wouldn't drop down an energy level.
(C) and (D)-Not sure where these answers even came from.
The actual reason behind the radius of a positive ion being smaller than the radius of its neutral atom is that the repulsive force between the electrons themselves is decreased, causing them to move closer together.