Periodic Table Basics

How did chemists change Mendeleev’s periodic table in the early 1900s?

• They included chemical properties such as bonding power.

• They included physical properties such as melting point and density.

• They used atomic mass instead of atomic number to organize the elements.

• They used atomic number instead of atomic mass to organize the elements.

The elements in a column of the periodic table

• have similar properties.

• are in the same period.

• have the same atomic mass.

• have very similar chemical symbols.

What information in the periodic table indicates the number of protons in an atom?

• the position of the element in its column

• the element’s chemical symbol

• the element’s atomic number

• the element’s atomic mass

Most metals are NOT

• ductile.

• good conductors of heat and electricity.

• liquid at room temperature.

• malleable.

Which group contains the most elements?

• semimetals

• nonmetals

• metals

• transition elements

In the periodic table, the most reactive metals are found

• in Group 1, the first column on the left.

• in Period 1, the first row across the top.

• in Groups 13 through 16 in the center.

• in Periods 6 and 7 at the bottom.

The elements that do not ordinarily form compounds are

• elements in the carbon family.

• metals.

• halogens.

• inert gases.

How many protons does an atom with an atomic number of 23 and a mass number of 51 have?

• 23

• 28

• 51

• 74

An atom has no overall charge if it contains equal numbers of

• electrons and protons.

• neutrons and protons.

• neutrons and electrons.

• None of the above

Which statement about neutrons is true?

• Neutrons have a mass of 1 amu.

• Neutrons circle the nucleus of an atom.

• Neutrons are the only particles that make up the nucleus.

• Neutrons have a negative charge.