Lesson 1

Question 1

Science

Answer 1

the study of the physical and natural world through observations and experiments

Question 2

Chemistry

Answer 2

the study of matter and its transformations

Question 3

Matter

Answer 3

any substance that has mass and takes up space by having volume. Matter is composed of atoms.

Question 4

Pure substance

Answer 4

matter that is composed of molecules that are all the same (elements and compounds)

Question 5

Mixtures

Answer 5

contains more than one pure substance that are combined (but do not form bonds to form compounds or molecules of all the same type)

Question 6

Homogeneous mixture

Answer 6

a mixture that appears uniform

Ex: salt dissolved in water

Question 7

Heterogeneous mixture

Answer 7

a mixture that has visibly different parts (ex: water and oil)

Question 8

Daltons Atomic Theory

Answer 8

1. matter is composed of indivisible atoms
2. An element contains only one type of atom
3. atoms of different elements have different properties
4. compounds consist of atoms of two or more elements in a whole-number ratio
5. atoms are neither created or destroyed in a chemical reaction

Question 9

Law of conservation of matter

Answer 9

Cannot create or destroy atoms

Question 10

Law of constant composition

Answer 10

compounds have atoms in the same ratio of elements

Question 11

Law of multiple proportions

Answer 11

You can form more than one compound with the same elements but in different ratios

Question 12

J. J. Thomson

Answer 12

showed the existence of electrons through a cathode ray tube

showed atom is divisible

Question 13

electrons

Answer 13

based on J.J. Thomson’s observations
1. negatively charged particles
2. less massive than atoms
3. electrons are indistinguishable regardless of the source (atom type)
∴electrons are fundamental constituents of all atoms

Question 14

R. A. Millikan

Answer 14

Oil drop experiment

found the charge and mass of an electron

Question 15

J. J. Thomson (atom model)

Answer 15

Plum pudding model

theorized electrons were in a cloud of positively charged matter (like plum pudding)

Question 16

Gold foil experiment

Answer 16

alpha particle (no electrons only protons and neutrons) beam aimed at thin gold foil
most went through but some deflected
reason for the nuclear atom

Question 17

The Nuclear Atom

Answer 17

• Most of the atom is empty space
• deflected particles are caused by a positively charged region (the nucleus)
• the nucleus is very small

Question 18

p, n ,e⁻⁻

Answer 18

p=protons=# e⁻⁻ in a neutral atom
n = neutrons
e⁻⁻ = protons in a neutral atom = atomic # in a neutral atom
mass number = protons+neutrons

Question 19

ⁿᵣ X

Answer 19

n is the mass #

r is the atomic #

Question 20

Isotope

Answer 20

atoms of the same element, with the same number of protons, but a different number of neutrons

Question 21

atomic mass (from isotopes amounts)

Answer 21

(a/100) M₁ + (b/100) M₂ = M
a is percent of first isotope, M1 is mass # of first isotope
b is percent of the second isotope, M2 is mass # of second isotope
M is the final molar mass

Question 22

Ions

Answer 22

an atom or group of atoms that carry a net positive or negative charge

Question 23

Cation

Answer 23

positive ion

loses e-

Question 24

Anion

Answer 24

negative ion

gain e-

Question 25

Group

Answer 25

column/family of periodic table

Question 26

period

Answer 26

row of periodic table

Question 27

group 1

Answer 27

alkali metals | highly reactive, one electron in outer layer

Question 28

group 2

Answer 28

alkali earth metals very reactive 2e- in outer layer

Question 29

transition metals

Answer 29

middle metals | group 3-12

Question 30

group 7

Answer 30

halogens highly reactive + electro negative react with metals to form salts 7 e- in outer layer

Question 31

group 8

Answer 31

noble gases most stable 8 e- in outer layer