Chapter 2: Chemistry of Life

Question 1

Chemistry

Answer 1

study of the structure and interactions of matter

Question 2

Matter

Answer 2

anything that takes up space and has mass

Question 3

Element

Answer 3

a substance that cannot be broken down into other substances by chemical reactions

Question 4

Most common elements in the human body are?

Answer 4

Oxygen, carbon, and Hydrogen

Question 5

Atom

Answer 5

structural unit of matter, consist of neutrons, protons, and electrons in different proportions

Question 6

Protons

Answer 6

positively charged and stay in the nucleus; have mass

Question 7

Neutrons

Answer 7

not charged (neutral) and stay in the nucleus; have mass

Question 8

Electrons

Answer 8

negatively charged; orbit nucleus; have very, very little mass

Question 9

Atomic Number

Answer 9

protons, defines which element is which. Ex:

Question 10

of electrons =

Answer 10

of protons

Question 11

Mass Number

Answer 11

of protons + # of Neutrons

Question 12

Isotopes

Answer 12

elements that have different mass numbers and hence different numbers of neutrons. Ex: Oxygen (O) can have 3 different mass numbers. Oxygen-15, Oxygen-16, Oxygen-17, are all stable isotopes of oxygen

Question 13

Radioactive isotopes

Answer 13

unstable isotopes

Question 14

Half-life

Answer 14

the time it takes for half of the radioactive materials to decay

Question 15

Electron shells

Answer 15

2,8,8

Question 16

Ions

Answer 16

Charged atoms

Question 17

Cations

Answer 17

elements with a positive charge; from losing an electron. Ex:

Question 18

Anions

Answer 18

elements with a negative charge, from gaining an electron. Ex: onions bad=negative

Question 19

Molecule

Answer 19

2 ore more atoms join together. Ex:

Question 20

Compound

Answer 20

2 or more elements get together, NaCl

Question 21

ionic bond

Answer 21

transfer or acceptance of electrons; breaks into cations and anions; conducts electricity; NaCl. Ex: one element of the ionic bond will give electrons and the other will take the electrons

Question 22

Noble gas

Answer 22

element with a full outer shell that doesn’t react with other elements; neon

Question 23

Nonpolar covalent bonds

Answer 23

share electrons evenly

Question 24

Single bonds

Answer 24

atoms share 1 pair of electrons. Ex: H-H. Hydrogen has an atomic # of 1, so it has one electron and one proton

Question 25

Double Bonds

Answer 25

atoms share 2 pairs of electrons. Ex: O-O. Oxygen atomic # = 8, has 8 protons and 8 electrons. Oxygen will have 2 electrons on the first shell, 6 in the second shell, so it’ll gain 2 more electrons

Question 26

Triple Bonds

Answer 26

atoms share 3 pairs of electrons. Ex: N-N. Nitrogen Atomic # = 7, has 7 electrons to start with, 2 in the first shell and 5 in the second shell. It wants to gain 3 and become N^-3

Question 27

Polar Covalent bonds

Answer 27

share electrons unevenly. Ex: H2O. Oxygen A#=8; Hydrogen A#=1

Question 28

Hydrogen Bonds

Answer 28

an attraction between a H and an O that are already bonded to other elements. Ex: H2O

Question 29

By exchanging electrons:

Answer 29

atoms can combine to form different chemicals