Chemistry Review

What would be the result of adding one proton to an atom?

• one electron would be added

• the total mass of the atom would decrease

• the atomic number would change

• the electrical charge would become neutral

An atom would lose the least amount of mass if it lost

• a proton

• a neutron

• a nucleus

• an electron.

Which properties are MOST affected by the number of electron orbitals around a non-metal atom?

• nuclear

• physical

• chemical

• radioactive

The half-life of uranium-238 is 4.5 billion years. The half-life of potassium-40 is 1.25 billion years. A rock is found with half of its original potassium-40 content. How much of its original uranium-238 content remains in the rock?

• more than 50%

• between 25% and 50%

• between12.5% and 24.9%

• less than 12.5%

The frequency of a line in the emission spectrum of an atom indicates the amount of

• charge characteristically lost when an electron drops to a lower energy state.

• energy characteristically released when an electron drops to a lower energy state.

• kinetic energy gained by the nucleus when heat energy is added to the atom.

• energy released by the nucleus when heat energy is removed from the atom.

Hydrogen (H) forms a compound with fluorine (F) which includes one atom of each element. Which other element MOST likely bonds with hydrogen in the same ratio?

• lithium (Li)

• sulfur (S)

• bromine (Br)

• neon (Ne)

Which metalloid is used in solar cells and computer chips?

• silicon

• silver

• arsenic

• antimony

What physical property distinguishes elements on the left side of the Periodic Table of the Elements from elements on the right side?

• number of protons

• state of matter

• atomic mass

• temperature

Oxygen reacts with iron to produce rust and with hydrogen to produce water. Which statement describes both reactions?

• A different mixture is formed in each case.

• A different solution is formed in each case.

• Both a change of state and of elements is involved.

• New molecules are formed but the same elements exist.

Missy and Ethan discussed examples of the types of changes in matter. In which example is a chemical change taking place?

• A piece of metal is cut in half.

• An ice cube melts on a counter.

• A camper roasts marshmallows over a burning fire.

• A baker mixes together flour and sugar to make dough.