Chemistry Review

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

• Element
• Atom
• Molecule
• Compound

Tags

NGSS.HS-PS1-7

In the atom diagram shown, E is pointing to

• An electron
• a proton
• a neutron
• the nucleus

Tags

NGSS.MS-PS1-1

B and C are found in the ______ of an atom.

• electron cloud
• Space
• Nucleus
• Outside

Tags

NGSS.MS-PS1-1

What is the atomic mass of this atom?

• 1

• 3

• 4

• 7

Tags

NGSS.MS-PS1-1

What is the atomic number of this atom?

• 4
• 5
• 9
• none of the above

Tags

NGSS.MS-PS1-1

What is a valence electron?

• an electron that is found in the outermost orbital of an atom. 
• an electron found in the innermost orbital of an atom.
• an electron found in the middle orbital.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1

An ionic bond forms when

• valence electrons are shared back and forth (move between) two atoms.

• a sea of mobile electrons surround the cations and they then become negativly charged

• valence electrons are transferred from one atom to another, forming charged ions that are then pulled together by attraction between opposite charges

• none of the above

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-3

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

Using the information provided, determine how many electrons the a Boron atom contains.

• 2.5

• 5

• 6

• 10.81

Tags

NGSS.MS-PS1-1

What makes a molecule polar?

• Equal sharing of valence electrons
• Unequal sharing of valence electrons
• Stealing of electrons
• Temporary charges that come and go

Tags

NGSS.MS-PS1-1