Chapter 2

Question 0

What are the three forms of matter?

Answer 0

1) Liquid ie: blood
2) Solid ie: bones
3) Gas ie: air we breathe

Question 1

What is matter?

Answer 1

Anything that occupies space and has a mass. The mass of an object is the matter of the object, living or nonliving and remains constant.

Question 2

Define energy

Answer 2

The capacity to do work, to put matter into motion. The greater the work done, the more energy is used doing it.

Question 3

What are the forms of energy? (2 main 4 other)

Answer 3

Main two:
1- kinetic energy: Is energy in action, Active.
2- potential energy: Stored energy, Inactive.
3- chemical energy: stored in bonds of chemical substances
4- electrical energy: comes from movement of charged particles
5- mechanical energy: is directly involved in moving matter
6- radiant energy: aka Electromagnetic energy, which is energy that travels in waves.

Question 4

Describe Elements.

Answer 4

All matter is composed of elements, which are unique substances that cannot be broken down into simpler substances by ordinary means. There are 118 total and 92 found occurring
Naturally.
- C,H,O,N make up 96% of body weight.

Question 5

What are atoms?

Answer 5

They are buildings blocks, more or less identical particles that make up elements. Have atomic symbols ie: K is potassium.

Question 6

What is the atomic structure of an atom made up of?

Answer 6

It is made up of a cluster of small particles:

• central nucleus (contains protons & neutrons tightly bound)
• electrons ( orbit around the nucleus with a negative charge)
• protons has a positive charge
• neutrons are neutral

Question 7

Describe atomic number.

Answer 7

It is equal to the number of protons in the nucleus. It is written to the left of its atomic symbol.

Question 8

What is the mass number of an atom?

Answer 8

The sum of the masses of its protons and neutrons.

Question 9

What is the atomic weight of an atom?

Answer 9

The average of the relative weights (mass numbers) of all isotopes of an element.

Question 10

What is a chemical bond?

Answer 10

Bonds that hold atoms together when they combine. The energy relationships of the electrons of the reacting atoms.

Question 11

What is the octet rule?

Answer 11

The electron shell must have a total of 8 electrons to be considered full.
-exception: shell one, which only contains 2 when full.

Question 12

Describe ions.

Answer 12

Is when electrons are transferred from one atom to another and the precise balance of + and - charges is lost so that charged particles are formed.

Question 13

What is an ionic bond?

Answer 13

A chemical bond between atoms formed by the transfer of one or more electrons from one atom to the other.
-metallic elements.

Question 14

What is an anion?

Answer 14

The atom that gains one or more electrons, the electron acceptor, & acquires a net negative charge.

Question 15

What is a cation?

Answer 15

The atom that loses electrons (electron donor) and acquires a net positive charge.

Question 16

Describe covalent bonds.

Answer 16

Electron sharing produced molecules in which the shared electrons occupy a single orbital common to both atoms.

Question 17

What is the difference between nonpolar and polar molecules?

Answer 17

Nonpolar: during covalent bonds electrons are shared equally

Polar: during covalent bonds electrons are shared unequally
IE: water

Question 18

Describe hydrogen bonds

Answer 18

They only form when the Hydrogen atom, is covalently linked to one electronegative atom, that is attracted by another atom (usually nitrogen or oxygen).
-surface tension is an example and is when the water molecules cling together to form films.

Question 19

What is a chemical reaction?

Answer 19

Whenever chemical bonds are formed, rearranged or broken.

Question 20

Describe what chemical equations are.

Answer 20

A symbolic way to write out chemical rxns.

Question 21

What are reactants in a chemical equations?

Answer 21

The number and kinds of reacting substances.

Ie: H+H =H2
Reactant^

Question 22

What are products in a chemical equation?

Answer 22

What is formed from combining reactants: molecules or compounds.

Ie: H+H =H2
^ Products

Question 23

What is synthesis?

Answer 23

When atoms or molecules combine to form a larger, more complex molecule. AKA combination reaction.

Ie: a+b= ab

Question 24

What is a decomposition reaction?

Answer 24

Occurs when a molecule is broken down into smaller molecules or down to its atoms.

ab –> a +b

Question 25

Describe exchange reactions

Answer 25

AKA displacement reactions.
-involve both synthesis and decomposition; bonds are both made and broken

Ie: AB+C–>AC+B
AB+CD–>AD+CB

Question 26

What are oxidation reduction reactions?

Answer 26

AKA redox reaction
They are decomposition reactions in that they are the basis of all reactions in which food fuels are catabolized for energy(how ATP is produced)

Reactants that lose their electrons are referred to as ELECTRON DONOR(donor is then being oxidized)

Question 27

What are the reaction effectors of chemical reactions?(4)

Answer 27

1- Temperature ( increasing temp in a substance, increases the kinetic energy of its particles.)
2-Concentration ( the higher concentration of particles, the faster rxn will occur)
3- particle size ( smaller particles move faster and larger ones move slower)
4- Catalyst ( substances that increase the rate of chemical rxn, but that are not being broken down but still make rxn occur faster.) ie enzymes are catalysts in proteins