Chemistry Exam 2

Question 1

who was first to use the word “atom”

Answer 1

Democritus

Question 2

who discovered that matter consists on atoms, atoms can’t be created or destroyed, and atoms of elements have the same properties?

Answer 2

John Dalton

Question 3

who discovered electrons?

Answer 3

J.J. Thompson

Question 4

who discovered the nucleus?

Answer 4

Ernest Rutherford

Question 5

who found that electrons orbit the nucleus?

Answer 5

Niels Bohr

Question 6

who found the wave nature of electrons?

Answer 6

Louis de Broglie

Question 7

who discovered the nuetron?

Answer 7

James Chadwick

Question 8

modern structure of an atom

Answer 8

Electron Cloud Model

Question 9

what do you add to get the atomic mass of an element?

Answer 9

protons and nuetrons

Question 10

where are the protons in an atom?

Answer 10

nucleus

Question 11

where are the neutrons in an atom?

Answer 11

nucleus

Question 12

where are the electrons in an atom?

Answer 12

electron cloud

Question 13

what charge does the proton have?

Answer 13

positive

Question 14

what charge does the neutron have?

Answer 14

nuetral

Question 15

what charge does the electron have?

Answer 15

negative

Question 16

which particles in an atom have mass?

Answer 16

protons and neutrons

Question 17

what are ions? how do they form?

Answer 17

atoms that gain electrons (nonmetals) or lose electrons (metals)

Question 18

what is an atom?

Answer 18

smallest piece of matter that still has properties of the element

Question 19

what is an element?

Answer 19

matter that is composed of one type of atom

Question 20

how do you calculate the charge of an atom or ion?

Answer 20

protons - electrons or compare protons and electrons

Question 21

atomic number=

Answer 21

protons and electrons

Question 22

what are valence electrons?

Answer 22

outer energy level electrons

Question 23

how many electrons fit in the first energy level?

Answer 23

2

Question 24

how many electrons fit in the second and third energy levels?

Answer 24

8

Question 25

what are the columns on the periodic table?

Answer 25

groups or families

Question 26

how do the elements within a column compare?

Answer 26

have similar chemical and physical properties

Question 27

what are the rows on the periodic table?

Answer 27

periods

Question 28

how do elements within a row compare?

Answer 28

they don't have much in common, range from metals to nonmetals (left to right)

Question 29

what are metals?

Answer 29

elements with 1,2, or 3 valence electrons

Question 30

where are metals located on the periodic table?

Answer 30

left side of the periodic table

Question 31

what are the physical properties of metals?

Answer 31

conduct heat and electricity, malleable, ductile, shiny luster

Question 32

what does ductile mean?

Answer 32

can be drawn/pulled into wires

Question 33

what does malleable mean?

Answer 33

can be hammered into sheets

Question 34

what are the alkali metals?

Answer 34

Li, Na, K, Rb, Cs, Fr

Question 35

where are alkali metals found on the periodic table?

Answer 35

group 1

Question 36

what are the alkaline earth metals?

Answer 36

Be, Mg, Ca, Sr, Ba, Ra

Question 37

where are the alkaline earth metals found on the periodic table?

Answer 37

group 2

Question 38

what are nonmetals?

Answer 38

elements with 5, 6, 7, or 8 valence electrons

Question 39

where are nonmetals found?

Answer 39

right side of the periodic table

Question 40

what are the properties of nonmetals?

Answer 40

bad conductors, dull, not malleable or ductile

Question 41

what does brittle mean?

Answer 41

if hit with a hammer it would fall apart or crumble

Question 42

what is the only nonmetal on the left side of the periodic table?

Answer 42

Hydrogen

Question 43

what are halogens?

Answer 43

F, Cl, Br, I, At

Question 44

where are halogens located on the periodic table?

Answer 44

group 17

Question 45

what are the noble gasses?

Answer 45

He, Ne, Ar, Kr, Xe, Rn

Question 46

where are the noble gasses located on the periodic table?

Answer 46

group 18

Question 47

what is chemical bonding?

Answer 47

2 or more atoms combine to make a new substance with different properties

Question 48

what part of an atom is involved in chemical bonding?

Answer 48

electrons

Question 49

what is the purpose of chemical bonding?

Answer 49

to have a full outer ring

Question 50

what are the two types of chemical bonding?

Answer 50

ionic and covalent

Question 51

what is ionic bonding?

Answer 51

two or more ions combine to form a neutral compound, (metals give up electrons, nonmetals take electrons)

Question 52

between which two types of elements does ionic bonding typically occur?

Answer 52

metals and nonmetals

Question 53

why do metals typically give up electrons?

Answer 53

they have few electrons in the outer ring

Question 54

why do nonmetals typically take in electrons?

Answer 54

almost full outer rings

Question 55

what is covalent bonding?

Answer 55

2 or more atoms share electrons

Question 56

how is covalent bonding different from ionic bonding?

Answer 56

covalent = sharing electrons ionic = give and take electrons

Question 57

between what types of atoms does covalent bonding occur?

Answer 57

nonmetals

Question 58

what is the difference between a single, double, and triple bond?

Answer 58

single = two shared electrons double = four shared electrons triple = six shared electrons

Question 59

what are the reactants?

Answer 59

elements/compounds before reaction

Question 60

where are reactants found?

Answer 60

left side

Question 61

what are the products?

Answer 61

elements/compounds after reaction

Question 62

where are products found?

Answer 62

right side

Question 63

what are subscripts and what do they tell you?

Answer 63

small numbers to the right, tells how many you have

Question 64

what are coefficients and what do they tell you?

Answer 64

big number to the left of each compound/element, tells how many molecules you have

Question 65

what does the law of conservation of mass say?

Answer 65

mass of all reactants must equal the mass of all products

Question 66

what is an acid?

Answer 66

substance that produces hydrogen ions pH = 0-6

Question 67

what is a base?

Answer 67

substance that produces hydroxide pH = 8-14

Question 68

what are compounds?

Answer 68

2 or more substances chemically combined

Question 69

what are mixtures?

Answer 69

2 or more substances physically combined

Question 70

what is the difference between homogeneous and heterogeneous?

Answer 70

homo = substance looks the same hetero = different materials can be easily seen

Question 71

3 examples of heterogeneous mixtures

Answer 71

- pizza - fruit salad - trail mix

Question 72

3 examples of homogeneous mixtures

Answer 72

- salt water - lemonade - steel