Chapter Two - Small Molecules and the Chemistry of Life

Question 1

what is an essential element?

Answer 1

an essential element is an element that is necessary for life

Question 2

what are the essential elements?

Answer 2

CHONPS
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur

Question 3

atoms

Answer 3

compose all matter

Question 4

electrons

Answer 4

negligible mass, negative charge, # of electrons = # of protons

Question 5

protons

Answer 5

found in the nucleus, have mass, positive charge

Question 6

neutrons

Answer 6

found in the nucleus, have mass, no charge

Question 7

the structure of an atom

Answer 7

an atom is composed of protons, neutrons, and electrons. the outermost regions of an atom are called electron cells and contain the electrons

Question 8

determine the atomic number, atomic mass, and number of neutrons for Sodium (Na)

Answer 8

atomic number: 11
atomic mass: 22
number of neutrons: 12

Question 9

how do isotopes of an element differ from one another?

Answer 9

isotopes of an element have different mass numbers due to their varying number of neutrons

Question 10

how do you determine how many electron shells an atom has?

Answer 10

based on its location in a row/period on the table

Question 11

determine how many electron shells Ca has

Answer 11

4

Question 12

why are valence electrons so important?

Answer 12

valence electrons are important because they determine the reactivity of an atom

Question 13

how many valence electrons does Carbon (C) have?

Answer 13

4

Question 14

what is the difference between a molecule and a compound?

Answer 14

a molecule is a group of two or more atoms of the same element held together by chemical bonds. a compound is a substance formed by two or more different types of elements which are united chemically at a fixed proportion

Question 15

covalent bonds

Answer 15

covalent bonds form by sharing one or more electron pairs to fill valence shells. they are very strong, and their orientation gives molecules their shape. they can be polar and nonpolar

Question 16

ionic bonds

Answer 16

ionic bonds form when one atom is MUCH more electronegative, can either be anions or cations

Question 17

hydrogen bonds

Answer 17

hydrogen bonds form due to the attraction between the - end of one molecule and the + end of another. these bonds are weaker than both covalent and ionic bonds. they play an important role in holding together the structure of DNA and proteins

Question 18

polar covalent bonds

Answer 18

polar covalent bonds involve the unequal sharing of electrons leading to a partial positive charge and partial negative across the covalent bond

Question 19

nonpolar covalent bonds

Answer 19

nonpolar covalent bonds are the equal sharing of electrons, as atoms have similar electronegativity

Question 20

reactants definition

Answer 20

what reacts together during a chemical reaction

Question 21

products definition

Answer 21

the results of a chemical reaction

Question 22

element

Answer 22

an element is a fundamental substance containing only one kind of atom

Question 23

atomic number

Answer 23

the number of protons in the nucleus of the atom, which determines the chemical properties of an element and its place in the periodic table

Question 24

atomic mass

Answer 24

atomic mass expressed in amu, approximately the number of protons plus the number of neutrons in the atom

Question 25

isotopes

Answer 25

isotopes are forms of an element with different numbers of neutrons and therefore different mass numbers

Question 26

ion

Answer 26

an atom or molecule with a net electric charge due to the loss or gain of one or more electrons

Question 27

orbital

Answer 27

an orbital

Question 28

valence shells

Answer 28

the energy shell farthest/outermost from the nucleus, a full valence shell = chemically stable = unlikely to react

Question 29

columns

Answer 29

group elements together based upon similar chemical properties/behaviors