AP bio Chapter 2

Question 1

Contrast the term element with Compound

Answer 1

Element- Substance that can’t be broken down to other substances through chemical reaction
Coumpound- 2 different elements combined

Question 2

contrast the term atomic mass and atomic number

Answer 2

atomic mass is the total sum of the number of neutrons and protons
atomic number is the number of protons in nucleus

Question 3

difference between atomic mass and weight

Answer 3

weight- average mass of atoms of an element

mass- number of neutrons and protons together

Question 4

what is an isotope

Answer 4

2 chemical elements with the same atomic number, but different atomic weights

Question 5

radioactive isotope

Answer 5

nuclei decay spontaniously which gives off particles of energy

Question 6

how are radioactive tracers used in science

Answer 6

diagnostic tools in medicine

used in biologically active molecules used to track atoms during metabolism

Question 7

explain how the movement of electrons relates to the concept of potential energy

Answer 7

An electrons energy level is correlated with it’s average distance to the nucleus. An electron can change the shell it occupies but only by absorbing or losing an amount of energy equal to the distance of potential energy between it’s position in the old shell.

Question 8

what determines interactions between atoms?

Answer 8

interactions are determined by the number of electrons in the valence shell, which effects chemical behavior

Question 9

Why are valence electrons important

Answer 9

They are important because they determine whether an atom will lose or gain electrons

Question 10

chemical bond

Answer 10

attraction between 2 atoms, share outer shell electrons

Question 11

covalent bond

Answer 11

bond where atoms share pairs of electrons

Question 12

single bond

Answer 12

a chemical bond in which 2 atoms share a pair of electrons

Question 13

double bond

Answer 13

a bond where atoms share 2 pairs of electrons

Question 14

valence

Answer 14

the bonding capacity of an atom, generally equal to the number of unpaired electrons in the atoms outermost shell

Question 15

electronegativity

Answer 15

the measure of the need of an atom to attract a bonding pair of electrons

Question 16

nonpolar covalent bond

Answer 16

bond that happens when 2 atoms with similar electronegativity share a pair of electrons

Question 17

polar covalent bond

Answer 17

covalent bond between atoms with different electronegativity, electrons pulled closer to greater one causing negative and positive

Question 18

what is the difference between structural and molecular formula?

Answer 18

molecular- shows what atoms are being used and how many

structural- shows types of bonds and graphic representation

Question 19

how do ionic bonds compare with covalent bonds

Answer 19

ionic bonds- electrons taken away from atom and given to another
covalent- bonded electrons are shared

Question 20

compare and contrast hydrogen bonds and van der waals interactions

Answer 20

hydrogen bond- weak bond, one electronegative atom, hydrogen atom, and another electronegative atom
van der waals- force between 2 or more non-polar molecules.
they are alike because molecular forces are similar, different cuz van der waals interactions can be strong, hydrogen bonds cant be

Question 21

what is an example of how molecular shape is critical in a living system

Answer 21

in the human brain it produces euphoria and relieves pain

Question 22

define a dynamic chemical equillibrium in terms of quantities of reactants and products

Answer 22

A chemical equilibrium is where the reactions equal each other exactly. The amount of products do not have to be equal, but most have a stabilized ratio. Reactions should equal each other out, the quantities should be in a ratio where the products leftover shouldn’t be greater or lesser than the original matter