Unit 8 and 9 Test. Physical Science (Atoms and Compounds)

Oxygen is a gas important for life and represents about 21% of Earth’s atmosphere. Which of the following illustrations below best represents a Bohr diagram of an oxygen atom?

• A
• B
• C
• D

Tags

NGSS.MS-PS1-1

ALL atoms of the same element have:

• same number of protons
• same number of electrons
• different number of neutrons
• different number of electrons

Tags

NGSS.MS-PS1-1

What are atoms composed of?

• Protons and electrons.
• Protons, neutrons, and electrons.
• Neutrons and electrons.
• Ions, elements, and compounds.

What charge does an atom have when it GAINS electrons?

• Positive
• Negative
• Neutral

Sodium has an atomic number of 11, how many protons does this atom have?

• 23
• 11
• 12
• 3

The following element key shows how many protons?

• 16
• 15.999
• Oxygen
• 8

Which is an electron?

• a
• b
• c

What is the mass number and name of an element with 8 protons and 8 neutrons?

• 16 - Carbon
• 16 - Oxygen
• 24 - Oxygen
• 8 - Neon

A tiny but very dense, positively charged portion of the atom that holds most of the atomic mass

• Electron Shells
• Orbitals
• Electron Cloud
• Nucleus

When two atoms of the same element have different masses, they are called ______, and have a different number of ______.

• Neutrons; Isotopes
• Atoms; Isotopes
• Isotopes; Protons
• Isotopes; Neutrons