Periodic

The atomic number of an element tells you ________

• the number of protons in the nucleus.

• the number of energy levels (electron shells).

• the number of neutrons in the nucleus.

• atomic mass.

How many valence (outer energy level) electrons do Alkaline Earth metals have?

• 1

• 2

• 7

• 8

Which of the following elements is an alkali metal?

• calcium

• magnesium

• mercury

• sodium

Mendeleev left gaps (open spaces) in his periodic table because

• the table was too small.

• protons belonged there.

• the table was too big.

• elements with the predicted properties hadn't been discovered yet.

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

• noble gases.

• alkali metals.

• radioactive elements.

• metalloids (semiconductors).

Most of the elements on the periodic table are ________

• metals.

• nonmetals.

• metalloids.

• semiconductors.

Elements in the same group (family) have similar ________

• atomic symbols.

• atomic sizes.

• atomic weights.

• chemical properties.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The order of elements in the modern periodic table is based on an element's ________

• atomic number.

• name.

• chemical symbol.

• atomic mass.

Which statement about the alkali metals is correct?

• They are located in the left-most column of the periodic table.

• They are extremely nonreactive.

• They are usually gases.

• They are halogens.

Which of the following properties best describes non-metals?

• often gases at room temperature

• shiny luster

• malleable

• good conductors of heat and electricity