Chemistry for Biology - Ch. 2

Question 0

Atoms

Answer 0

• smallest particles that retain the properties of an element
• made up of subatomic particles (proton, electron, neutron)

Question 1

Matter

Answer 1

• anything that occupies space and has mass

- is composed of chemical elements

Question 2

atomic number

Answer 2

number of protons in an element (note: # of protons equals the # of electrons in an uncharged atom)

Question 3

mass number

Answer 3

of protons + # of neutrons

Question 4

isotopes

Answer 4

atoms of an element that differ in mass (different # of neutrons)

Question 5

ion

Answer 5

charged atom; has lost or gained electrons
Loss = + ion
Gain = - ion

Question 6

molecule

Answer 6

atoms bonded together to fill their valence shell

Question 7

ionic bond

Answer 7

attraction between oppositely charged ions; electrons jump from one valence shell to valence shell of another, forming 2 ions

Question 8

covalent bond

Answer 8

atoms SHARE one or more pairs of valence electrons

Question 9

hydrogen bond

Answer 9

atom in one polar covalent molecule attracted to oppositely charged atom in another such molecule; water molecules stick to each other

Question 10

polar molecule

Answer 10

molecule with an unequal charge distribution (slightly negative end and slightly positive end)

Question 11

What are the 4 properties of water that make Earth “liveable”?

Answer 11

1. Cohesion/Surface Tension
2. Moderation of Temp
3. Expansion Upon Freezing
4. Versatility as a Solvent

Question 12

cohesion

Answer 12

attraction of molecules of the same kind; due to hydrogen bonds between water molecules

Question 13

Heat is ____ when Hydrogen bonds break

Answer 13

absorbed

Question 14

Heat is ____ when Hydrogen bonds form

Answer 14

released

Question 15

solute

Answer 15

substance being dissolved

Question 16

solvent

Answer 16

dissolving agent of a solution

Question 17

solution

Answer 17

homogenous mixture of substances

Question 18

What are cations and anions?

Answer 18

positively charged ion (cation) and negatively charged ion (anion)

Question 19

If [H+] is greater than amount of [OH-], what is the solution on the pH scale?

Answer 19

Acid (pH < 7)

Question 20

If [H+] is less than amount of [OH-], what is the solution on the pH scale?

Answer 20

Base (pH > 7)

Question 21

What does the pH scale being “logarithmic” mean?

Answer 21

There is a tenfold increase/decrease in pH

Question 22

What are the strongest and weakest bonds?

Answer 22

Strongest: Covalent
Weakest: Hydrogen

Question 23

Is something is 9 on a pH scale, is it acidic or basic?

Answer 23

Basic

Question 24

If something is 1 on a pH scale, does that make it acidic or basic?

Answer 24

Acidic

Question 25

The difference between the mass number and atomic number of an atom is equal to the number of _____

Answer 25

Neutrons

Question 26

What type of bond is it when Sodium and Chlorine bond to form NaCl?

Answer 26

Ionic bond

Question 27

When water dissociates, what does it dissociate into?

Answer 27

Hydrogen ions