Semester Review Standards

MOST elements on the periodic table are

• gas

• metals

• nonmetalss

Describe the location of non-metals on the periodic table?

• upper right corner

• middle

• lower left

Differentiate between metals and noble gases.

• Noble gases have a full shell of valence electrons while metals have only a few valence electrons.

• Valence electrons are different - metals have a full shell while noble gases have less than half a shell.

• Metals have a nearly full shell of valence electrons while noble gases have a half shell of valence electrons.

An antacid tablet was dropped in to plastic bag containing 10 ml at 22�C distilled water. The bag was immediately zipped closed and the chemical reaction proceeded until completion. Cite evidence to confirm that this was a chemical reaction.

• A gas was produced.

• The tablet disappeared.

• There was a color change.

Green plants give us oxygen to breathe using photosynthesis. Here is the unbalanced chemical reaction that occurs:
___CO₂ + ___H₂O → ___C₆H₁₂O_{6 + ___O2}

• 6,6,1,6

• 2,4,2,4

• 2,2,1,3

Give the correct balanced equation for the single replacement reaction of magnesium with aluminum oxide.

• 3Mg + Al₂O₃ → 3MgO + 2Al

• Mg + AlO → MgO + Al

• Mg + Al₂O₃ → MgO + Al

4 Al + 3O₂ → 2Al₂O₃

What does the "3" in front of O₂ stand for?

• It indicates that there are 3 separate oxygen molecules in the reaction.

• It indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction.

• It indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule.

Nuclear fusion, like the example here, produces huge amounts of energy. Consider the statements below. All BUT ONE statement provides more information about nuclear fusion.

• Nuclear fusion begins when a large, unstable nucleus is bombarded with a smaller particle.

• Nuclear fusion is responsible for the formation of the elements we classify in the periodic table.

• Nuclear fusion when used as an energy source does not produce particulate matter pollution like fossil fuel combustion.

What is the basic difference between a nuclear fission reaction and a nuclear fusion reaction?

• Fusion is a synthesis reaction while fission is a decomposition reaction.

• 
  Fusion is an exothermic reaction while fission is an endothermic reaction.

• Fusion does not generate energy while fission generates a huge amount of energy.diddedf

A radioactive isotope of potassium (K) has a half-life of 20 minutes. If a 40.0 gram sample of this isotope is allowed to decay for 80 minutes, how many grams of the radioactive isotope will remain?

• 2.5 grams

• 5.0 grams

• 10.0 gramsdhhj