Unit 1: Chapter R and 1

Question 1

SI Units

Answer 1

standard international

Question 2

mass

Answer 2

kg

Question 3

length

Answer 3

meter (m)

Question 4

time

Answer 4

seconds (s)

Question 5

temperature

Answer 5

Kelvin (K)

Question 6

Kelvin

Answer 6

• 0 Kelvin= absolute zero

- K= C + 273

Question 7

M

Answer 7

• mega
• 10 to the power of 6
• x million

Question 8

K

Answer 8

• kilo
• 10 to the power of 3
• x thousand

Question 9

c

Answer 9

• centi
• 10..-2
• one hundredth

Question 10

m

Answer 10

• milli
• 10..-3
• one thousandth

Question 11

μ

Answer 11

-micro
-10..-6
one millionth

Question 12

n

Answer 12

• nano
• 10..-9
• one billionth

Question 13

Sig Figs

Answer 13

• Significant Figures
  1. All non-zero numbers are sig figs
  2. A zero between non zero numbers is a sig fig (101)
  3. A zero after a non zero number may be a sig fig
• ADD/SUB= keep the least amount of sig figs after the decimal point
• MULT/DIV= keep the least amount of sig figs in your final answer
• put units!!

Question 14

density

Answer 14

• property for a pure substance that will never change
• d=m/v (mass/volume)\
• density unit= g/mL; g/cm; kg/L

Question 15

Dalton’s Atomic Theory

Answer 15

1. elements are composed of tiny indivisible particles called atoms. (false= protons and neutrons are smaller than atoms)
2. atoms of the same element are identical (false= isotopes= atoms that have the same numbers of protons but different numbers of neutrons)
3. Combination of elements (atoms) form a compound
   - Law of Definite proportions= 1:1 ratio when elements combine (ex; NaCl always 1:1)
   - Law of Multiple Proportions= ratio can change (smaller or larger) (ex; NO, N2O5)
4. chemical reactions occur due to the rearrangement of atoms

Question 16

Thompson’s model of the atom

Answer 16

• plum pudding model

- protons and electrons jumbled inside the atom

Question 17

Rutherford’s model of atom

Answer 17

• electrons surrounding it
• nucleus= protons and neutrons
• experiment= atom in center w/ gold foil surrounding it
• bean of alpha particles (positive charged) hit the atom
• most of them passed through (empty space)
• some reflected (hit another proton)
• huge positive charge in nucleus

Question 18

Atomic mass/mass number

Answer 18

-number of protons and neutrons

Question 19

atomic number

Answer 19

-number of protons

Question 20

protons

Answer 20

-subatomic particle with a positive charge

Question 21

electrons

Answer 21

-subatomic particle with a negative charge

Question 22

neutrons

Answer 22

-subatomic particle with no charge

Question 23

isotopes

Answer 23

• atoms with the same atomic number but different mass number