Water and Chemistry of Life

How many unique elements have scientists discovered to date?

• 96

• 108

• 118

• 128

Which of the following is the chemical symbol for chlorine?

• Ch

• Cl

• C

• Cr

Which four elements make up about 96% of living things?

• H, C, N, O

• C, O, S, Na

• H, O, Na, Cl

• K, Ca, Fe, Mg

Why do elements have unique properties?

• Because they have different numbers of neutrons

• Because their atoms have unique structures

• Because they form different bonds

• Because they exist in nature in pure form

Tags

NGSS.HS-PS1-1

What determines the identity of an element?

• The number of neutrons

• The number of protons

• The number of electrons

• The mass number

How many protons does a carbon atom have?

• 5

• 6

• 7

• 8

How many protons are in an oxygen atom?

• 6

• 7

• 8

• 9

Where are protons and neutrons located in the atom?

• In the electron shells

• In the nucleus

• Orbiting around the nucleus

• In the outer shell

Electrons in atoms are found:

• Inside the nucleus

• Spread randomly in space

• In shells around the nucleus

• Only in pairs with protons

Which statement about carbon is correct?

• Carbon's nucleus contains 7 protons

• Carbon’s electrons are found in three shells

• Carbon’s outer shell contains 4 electrons

• Carbon has no neutrons

Tags

NGSS.HS-PS1-1