Campbell Biology Chap 2

Question 1

What is an element

Answer 1

Substance that cannot be broken down to other substances by chemical reactions

Question 2

What is a compound

Answer 2

Substance Consisting of 2 or more different elements combined in a fixed ratio

Question 3

What is a Dalton

Answer 3

Essentially the same thing as an atomic mass unit(or AMU)

Question 4

What is an Isotope

Answer 4

Atoms with more neutrons than those of the same atoms

Question 5

What is a Radioactive Isotope

Answer 5

one in which the nucleus decays spontaneously, giving off particles and energy

Question 6

When the radioactive decay leads to a change in the
number of ____

Answer 6

Protons, Leading to the element to change into a different one

Question 7

A “parent” isotope decays into its “daughter” isotope at a
fixed rate, expressed as the ________ of the Isotope

Answer 7

Half-Life

Question 8

What is Radiometric Dating

Answer 8

Scientists measure the ratio of different isotopes and calculate how many half-lives (in years) have passed since an organism was
fossilized or a rock was formed

Question 9

Atoms are mostly

Answer 9

Empty Space

Question 10

_______ is the energy that matter possesses because of its location or structure

Answer 10

Potential Energy

Question 11

Matter has a natural tendency to move toward the ____
possible state of potential energy

Answer 11

Lowest

Question 12

Describe Electron shell

Answer 12

regions surrounding the atomic nucleus containing a specific number of electrons

Question 13

As electrons get farther away from the nucleus, how does the potential energy change

Answer 13

Increasing Potential Energy

Question 14

When an electron loses energy what happens

Answer 14

Moves to a lower shell

Question 15

When an electron gains energy what happens

Answer 15

Moves to higher shell

Question 16

What are valence electrons

Answer 16

number of electrons in its outermost shell

Question 17

Atoms with the same number of electrons in their valence shells do what

Answer 17

Exhibit similar behaviour

Question 18

Elements with a full valence shell are

Answer 18

Un-reactive

Question 19

What is the atomic mass of an element that has isotopes

Answer 19

average of their masses

Question 20

Describe covalent bonds

Answer 20

sharing of a pair of valence electrons by two atoms

Question 21

Strongest type of chemical bonds

Answer 21

Covalent Bonds

Question 22

First shell has a maximum of how many electrons

Answer 22

2

Question 23

Second shell has a maximum of how many electrons

Answer 23

8

Question 24

third shell has a maximum of how many electrons

Answer 24

18

Question 25

Formula for calculating maximum number of electrons in a given shell number

Answer 25

2n^2

Question 26

What is Electronegativity

Answer 26

the tendency of an atom participating in a covalent bond to attract the bonding electrons

Question 27

nonpolar covalent bond

Answer 27

When the Compound has elements of similar electronegativity

Question 28

polar covalent bond

Answer 28

When the compound has elements of different electronegativity

Question 29

What is an Ionic Bond

Answer 29

when two atoms are so unequal in their attraction for valence electrons that one of the atoms strips an electron from the other atom, which causes them to attract each other due to the formation of 2 ions of opposite charge

Question 30

positively Charged ion

Answer 30

Cation

Question 31

Negatively charged ion

Answer 31

Anion

Question 32

Compounds formed by Ionic bonding are also called

Answer 32

Salts

Question 33

Ionic compounds are not considered

Answer 33

Molecules

Question 34

Why do Hydrogen Bonds form

Answer 34

When a hydrogen atom is covalently bonded to an electronegative atom, the hydrogen atom has a partial positive charge that
allows it to be attracted to a different electronegative atom with
a partial negative charge nearby

Question 35

What are van der waal’s interactions

Answer 35

Nonpolar Covalent bonds exhibit unevenly distributed electrons, resulting in everchanging regions of positive and negative charge that enable all atoms and molecules to stick to one another