Ch 2 - Chemical Context of Life

Question 0

How many naturally occurring elements are there?

Answer 0

95

Question 1

Elements

Answer 1

Cannot be broken down into anything else

Question 2

How many elements are essential to life?

Answer 2

25

Question 3

What elements comprise 96% of living matter?

Answer 3

Hydrogen, carbon, nitrogen, and oxygen

Question 4

Atoms are comprised of subatomic particles:

Answer 4

Protons (+) and neutrons (neutral) in the nucleus; electrons (-) in the electron shells

Question 5

Valence shell

Answer 5

Outermost electron shell; the fewer electrons in this shell, the more reactive a given atom will be

Question 6

Electron shells

Answer 6

The fixed energy levels of an atom where the electrons reside

Question 7

Ionic bond

Answer 7

The transfer of electrons between two atoms so that each has a full valence shell

Question 8

Covalent bond

Answer 8

The sharing of electrons between atoms so that each has a full valence shell; stronger than an ionic bond

Question 9

Molecule

Answer 9

2+ atoms that form covalent bonds

Question 10

Van der Waals interaction

Answer 10

Occurs when transient positive and negative regions of molecules attract each other

Question 11

Example of the Van der Waals interaction

Answer 11

The ability of geckos to climb walls