Atoms & Periodic Table Review

Which of the following elements is an alkali metal?

• magnesium

• calcium

• sodium

• mercury

Which of the following elements is in the same period as phosphorus?

• oxygen

• carbon

• nitrogen

• magnesium

What does the number 84 in the name Krypton-84 represent?

• twice the number of protons

• the mass number

• the atomic number

• the sum of the protons and electrons

As you move from left to right across the periodic table, elements...

• have a lower atomic number

• become less metallic

• have a lower atomic weight

• become more metallic

Elements in an element family have similar...

• chemical properties

• atomic sizes

• atomic weights

• atomic symbols

The three main groups of elements are metals, nonmetals, and ...

• metalloids

• inert gases

• radioactive isotopes

• alkali metals

Which of the following categories includes the majority of the elements?

• liquids

• nonmetals

• metals

• metalloids

Mendeleev left gaps in his periodic table because...

• the table was too full

• no known elements fit there

• protons belonged there

• the table was too small

The smallest unit of an element that maintains the properties of that element is a(n)...

• compound

• atom

• molecule

• substance

The sum of the protons and neutrons in an atom equals the ...

• nucleus number

• atomic number

• mass number

• atomic mass