Chapter 2: Chemistry

Question 1

Elements

Answer 1

92 elements recognized to occur in nature

Question 2

Matter

Answer 2

anything that occupies space and has mass

Question 3

Compounds

Answer 3

consists of 2 or more different elements

Question 4

Trace Elements

Answer 4

Those needed in minutely small does (less than 100 mg/day)

Question 5

Iron (Fe)

Answer 5

needed by all forms of life

Question 6

Atoms

Answer 6

smallest portion of an element that still retains properties of that element

Question 7

Periodic Table

Answer 7

Elements are arranged by the atomic number (number of protons)

Question 8

Atomic Number

Answer 8

Number of protons (unique to each element) written on the bottom left

Question 9

Mass Number

Answer 9

Number of protons + neutrons; always written at the top left of the element symbol

Question 10

Atomic Mass

Answer 10

Total mass of an atom; generally we can ignore electrons due to their size

Question 11

Isotopes

Answer 11

An atom which has a different number of neutrons

Question 12

Radioactive Isotopes

Answer 12

nucleus decays spontaneously, giving off particles and energy

Question 13

Electron Shells

Answer 13

An energy level of electrons at a characteristic average distance from the nucleus of an atom

Question 14

Orbitals

Answer 14

The volume of space within an atom where the electron is likely to be (holds 2 electrons)

Question 15

Valence Shell

Answer 15

The outermost shell

Question 16

Chemical Bonds

Answer 16

The sharing of a pair of valence electrons by 2 atoms

Question 17

Covalent Bond

Answer 17

One or more electrons are shared between atoms

Question 18

Non-polar Covalent

Answer 18

Electrons are shared equally between the nuclei

Question 19

Polar Covalent

Answer 19

Electrons are shared unequally, creating partial electric charges

Question 20

Electronegativity

Answer 20

The attraction of a given atom for the electrons of a covalent bond

Question 21

Ionic Bonds

Answer 21

One or more electrons are transferred from one to another- the transfer allows the bond to form

Question 22

Hydrogen Bonds

Answer 22

A weak bond between a partial positive hydrogen and a partial negative atom

Question 23

Van der Waals Attractions

Answer 23

Attractions or weak bonds based on temporary partial charge within a single atom

Question 24

Photosynthesis

Answer 24

Solar powered rearrangement of matter

Question 25

Moderator of Temperature

Answer 25

Absorbs heat from air that is warmer and releasing the store heat to air that is cooler

Question 26

Thermal Energy

Answer 26

Kinetic energy associated with the random movement of atoms or molecules

Question 27

Temperature

Answer 27

Represents the average kinetic energy of molecules (regardless of volume)

Question 28

Cohesive Properties

Answer 28

Like-molecules are attracted to the same molecules

Question 29

Heat

Answer 29

Thermal energy in transfer from one body of matter to another

Question 30

Adhesive Properties

Answer 30

2 different molecules attracted to other molecules

Question 31

Evaporative Cooling

Answer 31

The conversion of liquid water into vapor using the thermal energy in the air, resulting in a lower air temperature

Question 32

Molecular Mass

Answer 32

The sum of the masses of all the atoms in a molecule

Question 33

Mole (mol)

Answer 33

Represents the exact number of objects: 6.02 x 10^23 (Avogadro’s Number) in one gram

Question 34

Molarity

Answer 34

The number of moles of solute per liter of solution

Question 35

pH

Answer 35

The measure of the hydrogen ion (H^+) concentration

Question 36

Acids

Answer 36

Substances that increases H^+ concentrations

Question 37

Bases

Answer 37

Substances that reduces H^+ concentrations

Question 38

Buffers

Answer 38

Substance in the cells which helps to maintain a relatively stable pH

Question 39

Ocean Acidification

Answer 39

Burning of the fossil fuels releases gaseous compounds into the atmosphere, which gets absorbed into oceans