Module One - Introduction and Measurement

Question 1

mega-

Answer 1

M

(10^6)m = 1 Mm

Question 2

kilo-

Answer 2

k

(10^3)m = 1 km

Question 3

centi-

Answer 3

c

1 m = (10^2) cm

Question 4

milli-

Answer 4

m

1 m = (10^-3) mm

Question 5

micro-

Answer 5

μ

1 m = (10^6)μm

Question 6

nano-

Answer 6

n

1 m = (10^9) nm

Question 7

pico-

Answer 7

p

1m = (10^12) pm

Question 8

True or False?

All nonzero digits are significant.

Answer 8

True.

4.356 has 4 significant figures.

Question 9

True or Flase?

Zeroes that appear between nonzero digits are NOT significant.

Answer 9

False.

Zeroes that appear between nonzero digits are significant.

93.003 has 5 significant figures.

Question 10

True or False?

Leading zeroes are not significant.

Answer 10

True.

0.0034 has 2 significant figures.

Question 11

True or Flase?

Trailing zeroes are not significant if there is a decimal point, but are significant if there isn’t.

Answer 11

Flase.

Trailing zeroes are significant if there is a decimal point, but are not if there is not a decimal point.

1200 has 2 significant figures. 1200.00 has 6, and 1200. has 4.

Question 12

How do we know how many significant figures to use in calculations?

Answer 12

Always use the measurement with the fewest sig figs as the baseline.

405. 68 - 9.0 = 396.7, because 9.0 has only one decimal place.
     (523. 98)*(12.1)*(0.0051) = 32 because 0.0051 has only two significant figures.

Question 13

An element is…

Answer 13

A substnce consisting of one kind of atom.

Question 14

An atom is…

Answer 14

The smallest particle of an element that retains the properties of that element.

Question 15

A compund is…

Answer 15

A pure chemical susbtance consisting of two or more different chemical elements.

Thse consist of a fixed ratio of atoms held in a spatial arrangement by chemical bonds.

Can be held together with ionic (like salt) or covalent (like water) bonds.

Question 16

A molecule is…

Answer 16

An electrically neutral group of at least two atoms in a definite arrangement that retains the composition and chemical characterstics of a compound.

Water consists of H2O molecules. Some elements can be diatomic molecules too, like hydrogen gas.

Question 17

A physical property is…

Answer 17

A characteristic of matter that is not associated with a change in chemical composition.

Boiling and melting points, electrical conductivity, density, color, and hardness are all physical properties.

Question 18

A physical change is…

Answer 18

A change in a state of matter wihout an accompanying chemical change.

The meting of wax, magnetizing/demagnetizing, or the dissolution of sugar in water are physical changes.

Question 19

A chemical property is…

Answer 19

A change of one matter into another.

Flammability, toxicity, acidity, reactivity, and heat of combustion are all chemical properties.

Iron forming with the oxygen in water to form rust, or nitroglycerine being super explosive are chemical properties.

Question 20

A chemical change is…

Answer 20

A change that produces one or more types of matter that differ from the matter present before the change.

All reactions and combustins, food rotting, rust forming or nitroglyerine exploding are all chemical changes.

Question 21

Whats the difference between metals, nonmetals, and metalloids?

Answer 21

Metals conduct well, nonmetals conduct poorly, and metalloids have properties of both.

Question 22

A salt is…

Answer 22

An ionic comound formed by the joining of an acid and a base.

NaCl is an ionic salt.