Which subatomic particle has a positive charge?

• Electron

• Proton

• Neutron

• Photon

Tags

NGSS.MS-PS2-3

What is the chemical symbol for the element oxygen?

• O

• Ox

• Oy

• Om

Which type of bond involves the sharing of electron pairs between atoms?

• Ionic bond

• Covalent bond

• Hydrogen bond

• Metallic bond

Tags

NGSS.HS-PS1-1

What is the pH of a neutral solution at 25°C?

• 0

• 3

• 7

• 14

Which property of water allows it to dissolve many substances?

• Nonpolarity

• High density

• Polarity

• Low boiling point

Tags

NGSS.HS-ESS2-5

Which of the following best describes a buffer?

• A substance that speeds up chemical reactions

• A solution that resists changes in pH when acids or bases are added

• A molecule that stores genetic information

• A type of ionic compound

Which statement correctly compares polar and nonpolar molecules?

• Polar molecules have equal sharing of electrons; nonpolar molecules have unequal sharing.

• Polar molecules have unequal sharing of electrons; nonpolar molecules have equal sharing.

• Both have unequal sharing of electrons.

• Both have equal sharing of electrons.

Fill in the blank: ______ are the smallest units of elements.

• Atom

• Element

• Electron

• Matter

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Kai is testing the acidity of a swimming pool and finds that the hydrogen ion concentration is very high. What is the pH of the pool water?

• 2

• 5

• 7

• 10

A scientist adds a strong acid to a buffered solution. What is the expected outcome and why?

• The pH will drop drastically because buffers cannot neutralize acids.

• The pH will remain relatively stable because the buffer neutralizes added acid.

• The pH will increase because acids make solutions more basic.

• The buffer will precipitate out of solution.