Chapter 2 Chemistry

Question 1

What is the difference between an Element and a Compound.

Answer 1

Element: Pure Substance, can’t be broken down by ordinary means

Compound: Two or more elements combined

Question 2

How many elements are essential to life?

Answer 2

25

Question 3

What elements make up 96 % of the life elements?

Answer 3

O, C, H, N, P, S (CHONPS) Carbo, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur

Question 4

What is Atomic Mass?

Answer 4

The number of protons and neutrons. It has decimals b/c there are different forms of the atoms

Question 5

What is Atomic Mass?

Answer 5

The number of protons and neutrons. It has decimals b/c there are different forms of the atoms

Question 6

What are an isotopes?

Answer 6

Atoms of the same element w/ dif. # of neutrons

Question 7

What determines the chemical properties of an atom?

Answer 7

The number of electrons in the outermost shell

Question 8

What is an ionic bond ?

Answer 8

occurs b/tw atoms when there is a transfer of electrons

Question 9

What is a positive ion called?

Answer 9

Cation

Question 10

What is a negative ion called?

Answer 10

anion

Question 11

What is a Covalent Bond?

Answer 11

when atoms share electrons

Question 12

Nonpolar Covalent Bond

Answer 12

atoms share electrons equally

Question 13

Polar Covalent Bond

Answer 13

atoms share have an unequal sharing of electrons due to electronegativity differences

Question 14

Hydrogen Bond

Answer 14

happens b/tw molecules due to unequal sharing of electrons & it contains a hydrogen atom

Question 15

Trace Elements

Answer 15

minerals present in living tissue in small amounts

Question 16

What is matter?

Answer 16

Any substance that has mass and takes up space

Question 17

Neutron

Answer 17

Subatomic particle found in the nucleus, it has no charge

Question 18

Proton

Answer 18

Subatomic particle in the nucleus, has a positive charge

Question 19

Electron

Answer 19

subatomic particle found on atoms shells w/ neg. charge

Question 20

Energy

Answer 20

ability to exert force that causes displacement of an object

Question 21

Electron Shells

Answer 21

The outside part of an atom around the nucleus

Question 22

Molecule

Answer 22

A group of atoms bonded together

Question 23

potential energy

Answer 23

energy held by an object because of its position relative to other objects

Question 24

Which has more PE water v. glucose

Answer 24

Glucose b/c more energy is stored in the chem bonds

Question 25

Which has more PE: Electron 1st or last shell?

Answer 25

Last b/c its farther from the nucleus

Question 26

What determines the chemical behavior of an atom?

Answer 26

Atomic Number & stability of nucleus

Question 27

Electronegativity

Answer 27

tendency of an atom in a molecule to attract the shared pair of electrons towards itself.

Question 28

What is van der Waals forces/interaction ?

Answer 28

Relatively weak electric forces that attract neutral molecules to one another in gases, in liquefied and solidified gases

Question 29

What is polar molecule

Answer 29

A molecule that is slightly pos. on 1 end and slightly neg. in another end.

Question 30

How many hydrogen bonds can a single water molecule form?

Answer 30

4 hydrogen bonds

Question 31

What does the number of valence electrons tell you about the reactivity of an element?

Answer 31

Whether they tend to give up an electron or gain electron during chem. reactions.

Question 32

How do ions form?

Answer 32

The addition to or the removal of electrons from a neutral atom or molecules.

Question 33

What is a radioactive isotope? & 1 medical application

Answer 33

An unstable form of a chemical element that releases radiation as it breaks down to become more stable. Carbon-14 is used for various scanning devices

tracers within a living organism to trace what is going on inside the organism at an atomic level; When radioactive isotopes are injected