Unit 1 Test Review

An atom of ⁴⁰₁₈Ar has a nucleus that contains a total of

• 18 electrons

• 18 protons

• 18 neutrons

• 18 nucleons

The arrangement of the elements in the present Periodic Table is based on atomic

• mass

• number

• radius

• density

Different isotopes of the same element must have a different

• mass number

• atomic number

• number of protons

• number of electrons

In all samples of the element potassium, each atom has

• 19 protons

• 20 neutrons

• 39 protons and neutrons

• 39 nucleons

Tags

NGSS.MS-PS1-1

Use this element from the Periodic Table to answer the question. What is the atomic mass for silicon?

• 14.0

• 14.1

• 28.1

• 42.1

Tags

NGSS.HS-PS1-1

A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is

• 1

• 11

• 12

• 23

Tags

NGSS.MS-PS1-1

An atom that has an electron configuration of 1s²2s²2p⁶3s²3p⁶4s²3d⁵

• an alkali metal

• an alkaline earth metal

• a transition element

• a noble gas element

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Why are the noble gases so unreactive?

• Their outer shell has 1 electron.

• Their outer shell has 2 electrons.

• Their outer shell is filled.

• Their outer shell needs one electron to be full.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Within Period 2 of the Periodic Table, as the atomic number increases, the atomic radius generally

• decreases

• increases

• remains the same

Which is the electron configuration of an atom of a Period 3 element?

• 1s²2s¹

• 1s²2s²2p¹

• 1s²2s²2p³

• 1s²2s¹2p⁶3s¹

Tags

NGSS.HS-PS1-1