exam 1

Question 1

describes how close a measurement is to the true or known value

Answer 1

Accuracy

Question 2

How well several independent measurements agree with each other

Answer 2

Precision

Question 3

uncertain digit

Answer 3

last digit

Question 4

Fahrenheit to celsius formula

Answer 4

(F-32) / 1.8

Question 5

density of water at room temp?

Answer 5

1.00 g/mL

Question 6

periods

Answer 6

The horizontal rows

Question 7

Elements with similar properties are in the same column

Answer 7

group or family

Question 8

“Z” means

Answer 8

number of protons

Question 9

“A” means

Answer 9

protons + neutrons

Question 10

Group 1A

Answer 10

Alkali metals

Question 11

• Soft, shiny metals
• Are never found in nature in the pure state because they are highly reactive
• Are always found in combination with other elements

Answer 11

Alkali metals

Question 12

Group 2A

Answer 12

Alkaline Earth Metals

Question 13

• Lustrous, silvery metals
• Harder and denser than alkali metals
• Reactive, but less than Group 1

Answer 13

Alkaline Earth Metals

Question 14

• Is a non-metal
• Notice it is located at the top of Group 1A, but it is not part of that group.
• It is the first element of the periodic table because it has the smallest mass
• It is a colorless and odorless gas
• Most abundant element in the universe
• Highly flammable and will burn in air
• It exists in nature as two atoms combined

Answer 14

Hydrogen

Question 15

• Most important element to sustain life
• Colorless and odorless gas
• It exists in nature as two atoms combined

Answer 15

Oxygen

Question 16

• Colorless and odorless gas
• It is a liquid when kept under pressure but a gas at room temperature
• Important is many industrial applications, particularly in fertilizers
• It exists in nature as two atoms combined = N2

Answer 16

Nitrogen

Question 17

• Colorful, non-corrosive non-metals
• All diatomic = meaning 2 atoms  F2, Cl2, Br2, I2
• Found combined with other elements in nature
• F2 and Cl2 are gases
• Bromine is a liquid at room temp = Br2 (l)
• Iodine a dark, purple solid at room temp = I2 (s)

Answer 17

Group 7A: Halogens

Question 18

• Are all gases at room temp

* Very unreactive, practically inert

Answer 18

Group 8A: Noble Gases

Question 19

• The most stable element form is called white phosphorous
• It exists as four P atoms attached together = P4
• Used in tear gas and explosives

Answer 19

P4, Phosphorous

Question 20

exists as 8 atoms attached together
• Used in gunpowder, matches, fireworks, and fertilizers
• Yellow solid

Answer 20

S8, Sulfur

Question 21

Solids at room temperature, except Hg
Reflective surface and are shiny
Conduct heat
Conduct electricity
Malleable (can be shaped)
Ductile (drawn or pulled into wires)

Answer 21

Metals

Question 22

Found in all 3 states (s, l, g )
Solids are brittle
Poor conductors of heat
Poor conductors of electricity

Answer 22

Non-metals

Question 23

Two elements that are liquid in nature

Answer 23

Mercury Hg and Bromine Br

Question 24

Diatomic elements

Answer 24

HNOF -ClBrI

Question 25

Ammonia

Answer 25

NH3

Question 26

Methane

Answer 26

CH4

Question 27

metals will only become

Answer 27

Cations

Question 28

non-metals will only become

Answer 28

Anions

Question 29

water boiling point

Answer 29

100 celcius