160 - 2.1 2 3

Question 1

· What are the basic building blocks of all matter?

Answer 1

Atoms

Question 2

· Describe the structure of an atom

Answer 2

Composed of three smaller particles: Protons, neutrons and electrons. The nucleus of an atom is made of protons and neutrons. A cloud of electrons surround the nucleus.

Question 3

· What is the difference between and atom and an element?

Answer 3

Atom - smallest piece of an element that retains the characteristics of an element. Element - substance that cannot be broken down by chemical means into other substances.

Question 4

Define Protons, including location in an atom

Answer 4

Positively charged particle in an atom’s nucleus

Question 5

Define Neutrons, including location in an atom

Answer 5

Electrically neutral particle in the atom’s nucleus

Question 6

Define Electrons, including location in an atom

Answer 6

Negatively charged particle that orbits the atom’s nucleus

Question 7

· Differentiate an element’s atomic number from mass number.

Answer 7

Atomic number indicates how many protons are in each atom of that element. An atom’s mass number is the total number of protons and neutrons in its nucleus.

Question 8

What is an isotope?

Answer 8

A different form of a single element. Element will have the same number of protons, but not necessarily the same number of neutrons.

Question 9

· Differentiate an atom from an ion/ When does an atom become an ion?

Answer 9

An atom becomes an ion when it loses or gains an electron

Question 10

Define Electronegativity

Answer 10

A measure of an atom’s ability to pull electrons from another atom.

Question 11

Define Chemical Bond

Answer 11

Attractive force which holds atoms together

Question 12

Define Molecule

Answer 12

Two or more atoms joined by chemical bonds

Question 13

Define Compound

Answer 13

Molecule that includes different elements

Question 14

Define Mixture

Answer 14

combination substances that are not chemically combined

Question 15

What is a covalent bond?

Answer 15

A bond in which atoms share electrons

Question 16

· How do atoms interact?

Answer 16

Atoms may donate, steal or share electrons to arrive at the right number, depending on the atom’s electronegativity

Question 17

· Name and describe the 3 kinds of bonds with examples.

Answer 17

Ionic (sodium chloride), Covalent (water), Hydrogen (between water molecules)

Question 18

· Why is water essential to life? List and explain the factors that contributes to Water’s life giving properties. 5

Answer 18

Its extraordinary properties make it essential to all organisms.
Factors:
Cohesive and adhesive; water molecules stick together, give surface tension, tendency to form H bonds with other substances.
Solvent: dissolves hydrophilic solutes, ions.
Regulates temperature: H bonds resist temp change. Frozen water expands: less dense, aquatic life survives.
Participates in chemical reactions: photosynthesis, respiration

Question 19

Define Polarity

Answer 19

Separation of charge into distinct positive and negative regions in a polar covalent molecule. (i.e. water)

Question 20

Define Hydrophobic

Answer 20

Repelled by water, do not dissolve in or form hydrogen bonds with water

Question 21

Define Hydrophilic

Answer 21

Attracted to water, polar or charged, readily dissolve in water

Question 22

Define Solution

Answer 22

solutes dissolved in a solvent

Question 23

Define Solute

Answer 23

A chemical that dissolves in a solvent forming a solution

Question 24

Define Solvent

Answer 24

A chemical in which other substances dissolve

Question 25

Define Cohesion

Answer 25

Attraction of water molecules to one another

Question 26

Describe a polar covalent bond

Answer 26

Atoms with different electronegativity do not share electrons equally; one atom has a more negative charge, the other is more positive

Question 27

Describe a non-polar covalent bond

Answer 27

Atoms sharing electrons equally; formed between atoms with identical electronegativity

Question 28

Describe a hydrogen bond. 4

Answer 28

• -A weak attraction between a highly electronegative atom and a hydrogen atom taking part in a separate polar covalent bond
• -Are not chemical bonds.
• -Stabilize the structures of large biological molecules
• -Account for water’s unique properties.