Unit 2 Basic chemistry

Question 1

define matter

Answer 1

anything that occupies space and has a mass

Question 2

Define Element

Answer 2

substance that cannot be broken down into other substances by normal chemical means

Question 3

define compound

Answer 3

substance consisting two or more elements in a fixed ratio

Question 4

what is the minimum amount of components for a living organisms

Answer 4

at least 3 or 4 elements

Question 5

how many elements do humans need for life

Answer 5

25 elements

Question 6

what are the big 6 elements that make up 99% of the matter in our bodies

Answer 6

• oxygen
• carbon
• hydrogen
• nitrogen
• calcium
• phosphorus

Question 7

what elements are used in blocks of protein, carbohydrates, and lipids

Answer 7

Oxygen, carbon, hydrogen, nitrogen

Question 8

what element is important in DNA

Answer 8

Phosphorus

Question 9

what elements are important in Bones and Teeth

Answer 9

Phosphorus and calcium

Question 10

Define atoms

Answer 10

smallest unit of matter that still retains the properties of an element

Question 11

what kind of subatomic particles can an atom be split in?

Answer 11

1. Proton
2. Electron
3. Neutron

Question 12

define a proton

Answer 12

single positive electrical charge

Question 13

define electron

Answer 13

single negative electrical charge

Question 14

define neutron

Answer 14

electrical neutral

Question 15

what is the atomic number

Answer 15

number of protons in an atom

Question 16

what is a mass number

Answer 16

sum number of the protons and neutrons in a nucleus

Question 17

define an Isotope

Answer 17

Atoms that have same number of protons and behave the same way chemically but have different numbers of neutrons

Question 18

what are radioactive isotopes

Answer 18

the nucleus of the atom is unstable and decays spontaneously

Question 19

define a valence shell

Answer 19

the outer shell of an atom

Question 20

define valence electrons

Answer 20

electrons found on a valence shell

Question 21

define inert atoms

Answer 21

atoms that have complete outer shells

Question 22

define chemical bonds

Answer 22

attractions and interactions between atoms

Question 23

define Ionic bonds

Answer 23

transfer of electrons from one atom to another

Question 24

define Covalent bonds

Answer 24

sharing of electrons between atoms

Question 25

define molecule

Answer 25

two or more atoms bound together by covalent bonds

Question 26

electronegativity

Answer 26

an atoms measure of attracting for shared electrons

Question 27

Define nonpolar covalent bonds

Answer 27

electrons are shared equally because the two atoms have the same electronegativity

Question 28

define polar covalent bonds

Answer 28

electrons are pulled closer to the more electronegative element

Question 29

define Ion

Answer 29

atom with an electrical charge due to gain or loss of electrons

Question 30

define salt

Answer 30

any ionic compound

Question 31

define hydrogen bonds

Answer 31

-weak bonds within and between polar molecules
- always involve the atom hydrogen
- hydrogen is most often attracted to oxygen and nitrogen

Question 32

define a chemical reaction

Answer 32

breaking existing chemical bonds and forming new ones

Question 33

define reactants

Answer 33

starting materials

Question 34

define products

Answer 34

the materials that result from the chemical reaction

Question 35

Define balanced chemical equation

Answer 35

the same number of atoms on both sides are equal