Ch.2: Chemistry

Question 1

anything that takes up space and has mass

Answer 1

matter

Question 2

a substance consisting of two or more elements in a fixed ratio

Answer 2

Compound

Question 3

a substance that cannot be broken down

Answer 3

element

Question 4

About ___ of the 92 elements are essential to life

Answer 4

25

Question 5

What four elements make up 96% of living matter

Answer 5

Carbon, hydrogen, oxygen, and nitrogen

Question 6

those required by an organism in minute quantities

Answer 6

Trace elements

Question 7

Most of the remaining 4% consists of

Answer 7

calcium, phosphorous, sulfur, and potassium

Question 8

s the number of protons in its nucleus

Answer 8

atomic number

Question 9

the atom’s total mass, can be approximated by the mass number

Answer 9

atomic mass

Question 10

the sum of protons plus neutrons in the nucleus

Answer 10

mass number

Question 11

are those in the outermost shell,

Answer 11

Valence electrons

Question 12

Elements with a full valence shell are chemically XXX. They don’t want to gain or lose any electrons

Answer 12

inert

Question 13

Interactions of valence electrons usually result in atoms staying close together, held by attractions called

Answer 13

Chemical bond

Question 14

A XXXXXXXX is the sharing of a pair of valence electrons by two atoms
In a covalent bond, the shared electrons count as part of each atom’s valence shell

Answer 14

covalent bonds

Question 15

The notation used to represent atoms and bonding is called a XXXXXX
For example, H–H

Answer 15

Structural formula

Question 16

This can be abbreviated further with a XXXXX

For example, H2

Answer 16

Molecular Formula

Question 17

an atom’s attraction for the electrons in a covalent bond

Answer 17

Electronegativity

Question 18

the atoms share the electron equally

Answer 18

non polar covalent bond

Question 19

one atom is more electronegative, and the atoms do not share the electron equally

Answer 19

Polar covalent bond

Question 20

Atoms sometimes strip electrons from their bonding partners
An example is the transfer of an electron from sodium to chlorine
After the transfer of an electron, both atoms have charges

Answer 20

Ionic bond

Question 21

A charged atom (or molecule) is called an

Answer 21

ionic bond

Question 22

is a positively charged ion

Answer 22

cation

Question 23

is a negatively charged ion

Answer 23

anion

Question 24

forms when a hydrogen atom bonded to one atom is also attracted to another
Water molecules are attracted to one another via H bonds.

Answer 24

hydrogen bonds

Question 25

Biological molecules recognize and interact with each other with a specificity based on

Answer 25

Molecular shape

Question 26

are the making and breaking of chemical bonds

Answer 26

chemical reactions

Question 27

6 CO2 + 6 H20 → C6H12O6 + 6 O2

Answer 27

carbon dioxide + water > glucose + oxygen