Chemistry Review

Which of the following is described as the basic unit of matter?

• Element
• Atom
• Molecule
• Compound

Tags

NGSS.HS-PS1-7

A molecule is________

• two ions held together by opposite charges
• smaller than an atom
• can be physically separated into smaller atoms
• more than one atom bonded together by covalent bonds

Tags

NGSS.MS-PS1-1

What charge does an electron have?

• Negative
• Positive
• Neutral
• Contrated

Tags

NGSS.MS-PS2-3

Which of the following is found in the nucleus of an atom?

• electrons
• neutrons
• The center of an atom, composed of protons and neutrons
• molecules

Tags

NGSS.HS-PS1-8

An ionic bond forms when 

• Valence electrons are shared
• a sea of mobile electrons surround the cations
• valence electrons are transferred between atoms
• none of the above

Tags

NGSS.HS-PS1-2

In chemical compounds, covalent bonds form when

• the electronegativity difference between two atoms is very large.
• electrons are completely transferred between two atoms.
• pairs of electrons are shared between two atoms.
• ions are held together by opposite charges.

Tags

NGSS.MS-PS1-1

This symbol indicates a _______.

• neutron

• proton

• electron

What 2 elements make up water?

• Hydrogen and Carbon

• Carbon and Oxygen

• Hydrogen and Oxygen

• Oxygen and Helium

Tags

NGSS.MS-PS1-1

An electron is located ...

• in the nucleus.

• outside the nucleus.

Tags

NGSS.MS-PS1-1

The atomic number of oxygen is

• 8

• 15.9994

• 16

• O