Concepts Flashcards
1
Q
How do you know how many electrons are in a “neutral” atom?
A
The same number as protons.
2
Q
Do atoms move?
A
Yes
3
Q
How many electrons are in the first energy level?
A
2
4
Q
How many electrons are in the second energy level?
A
8
5
Q
What is the atomic number and where can you find it?
A
It tells the number of protons in an atom and is found above the element’s symbol on the periodic table.
6
Q
What is the atomic mass of an atom and where can you find it?
A
It is the sum of the mass of the protons and neutrons and is found under the element’s symbol.
This book simplifies it a bit to counting protons and neutrons, but in real life, slightly different**
7
Q
What is the difference between weight and mass?
A
Mass is teh same anywhere in the universe; weight is affected by gravity.
8
Q
What is the difference between weight and mass?
A
Mass is the same anywhere in the universe; weight is affected by gravity.
9
Q
All things are made of chemicals
A
Chemicals, which are made of molecules, which are made of atoms of elements
10
Q
Chemistry is the science that studies chemicals
A
Chemicals
11
Q
A ____ is a person who studies how chemicals interact
A
Chemist
12
Q
A ________ is your best guess about the outcome of an experiment
A
Hypothesis
13
Q
Chemists use two types of tests to tell different things apart—physical tests and chemical tests
A
Physical tests and chemical tests
14
Q
Most chemicals are benign
A
TRUE
16
Q
<p>Atoms are extremely small</p>
A
True
17
Q
<p>Atoms are stationary</p>
A
False
18
Q
<p>A Greek philosopher named \_\_\_\_\_\_\_\_\_\_\_ talked about the concept of atoms 2,400 years ago</p>
A
Democritus
19
Q
<p>\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ affects how fast atoms move and the rate of diffusion</p>
A
Temperature
20
Q
<p>A \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is needed to see atoms</p>
A
21
Q
<p>The three parts of an atom are \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_</p>
A
protons, neutrons, and electrons
21
Q
Electrons are found orbiting the nucleus in ___________
A
energy levels
22
Q
<p>\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is/are found in the nucleus</p>
A
Protons and neutrons
23
Q
________ and _________ are charged particles
A
Protons and electrons
24
Q
<p>True or False: Protons, neutrons, and electrons are different depending on what atom they are in.</p>
A
False - a proton is a proton no matter what kind of atom it is in Same wiht neutrons and electrons.
25
Each type of ______ has a unique name
atom
26
Atoms are mostly _________________________
empty space
27
What makes one type of atom different from another type of atom?
The number of protons that the atom has in its nucleus
28
The number of __________ a neutral atom has is the same as the number of protons in its nucleus
electrons
29
An _________ is a group of the same type of atoms
element
30
A maximum of ________ electrons go in the first energy level
two
31
A maximum of __________ electrons go in the second energy level
eight
32
When going from one type of atom to the next, one and only one ______ is added to nucleus
proton
33
True or False: Most atoms have more than one energy level
True
34
The __________ is a chart that has the names of all the elements on it
periodic table
35
True/False: Everything is made from elements in the periodic table
True
36
Elements are on the periodic table in abbreviated forms, called _________
symbols
37
____________ invented the periodic table
Dmitri Mendeleev
38
Why do some symbols have nothing in common with the name for the element?
Some symbols come from earlier names used for the element
39
The ___________ is found on your periodic table above the symbol for the element
atomic number
40
The atomic number equals the number of _______ in that type of atom
protons
41
The number of electrons in an atom’s elemental form equals the ________________
atomic number
42
If something is an __________, all parts of it will react the same in a chemical test
element
43
When going from one element to the next one on the periodic table, one ________ is added to the nucleus
proton
44
The ___________ of an element equals the number of protons + the number of neutrons
atomic mass
45
True or False: Mass is the same anywhere in the universe
True
46
True or False: Weight is the same anywhere in the universe
False. Weight is affected by gravity, so it isn't the same anywhere in the universe.
47
Things that take up the same amount of space can have different ___________
masses
48
If the number of the same type of atoms stays constant, the liquid state weighs the SAME or MORE or LESS as the solid state
same
49
What does a.m.u. stand for?
atomic mass unit
50
________ is the unit used to measure the atomic mass of an atom
a.m.u. or atomic mass unit
51
The rows of the periodic table are called ________
periods
52
There are ______ periods on the periodic table
seven
53
True or false: The periodic table is read from left to right and down, like a book
True
54
The _______ an element is in equals the number of energy levels it has
period
55
The columns of the periodic table are called _______
groups
56
Elements in the same _______ on the periodic table share traits with each other
group
57
There are ______ groups on the periodic table
18
58
Elements in the same group have the same number of ____________________
electrons in their outer energy level
59
The top three _________ on the periodic table have 18 commonly occurring elements
rows (periods)
60
_________ of the 118 elements are naturally occurring, the rest are man-made
92
61
One and only one _____________ is added to the nucleus of an element when going from one element to the next on the periodic table
proton
62
The number of _______ in an element’s nucleus equals its atomic number
protons
63
The__________ of an element equals the atomic number plus the number of neutrons
```
atomic mass
(By the way, this is conceptual and simplified for kids, not exactly true. It's the total of the mass of the protons and neutrons, which is not exactly 1.)
```
64
The total number of ________ for elements on the periodic table equals the number of ______ for that element
electrons, protons
65
All elements in the same group have the same number of _____________________________
electrons in their outer energy level
66
The number of ________ does not increase consistently from one atom to the next, but does increase overall
neutrons
67
Introduction to the elements hydrogen, lithium, and sodium
Answer
68
Things are (more or less) buoyant in NaCl + water than in water alone
more
69
Introduction to the elements hydrogen, lithium, and sodium
Answer
70
A solution = ______ + ________
A solution = solute + solvent
71
________ is the universal solvent
Water
72
Introduction to the elements boron and aluminum
Answer
73
Introduction to the elements carbon and silicon
Answer
74
________ browns when heated
Carbon
75
Sugar is made from _____________
carbon, hydrogen, and oxygen
76
Introduction to the elements nitrogen and phosphorus
Answer
77
Introduction to the elements oxygen and sulfur
Answer
78
When hydrogen peroxide bubbles it is turning into ______________
water and O2
79
Hydrogen peroxide bubbles on cuts because of _________ in your blood, not germs in the cut
catalase
80
Introduction to the elements fluorine and chlorine
Answer
81
__________ bonds to calcium in teeth making teeth stronger
Fluorine
82
Introduction to the elements helium, neon, and argon
Answer
83
Gas SHRINKS or GETS BIGGER when it is cold
shrinks (has a smaller volume)
84
Atoms bond (link) together and make ________
molecules
85
The bonds form when atoms share _________________
electrons from their outer energy levels
86
A _________ is a group of all the same type of molecules
compound
87
A _________ is a group of different types of molecules
mixture
88
____________ tell the amount and type of atoms present in a molecule
Molecular formulas
89
To write a _______________, write the symbol for the element and the number of _______ present
molecular formula, atoms
90
___________ in plants is a result of the interaction between water molecules and the cellulose molecules in the plant
Capillary action
91
A special method for drawing molecules called that uses dots
Electron Dot Structures
92
When drawing molecules with Electron Dot Structures, place the atoms so they are sharing ______ on the side where there is a single electron
electrons
93
Electron Dot Structures pair _______ from different atoms using only _____________________
electrons,
| electrons in the atoms’ outer energy levels
94
The rate of ___________ can be affected by how “sticky” water finds molecules it encounters in something like a plant
capillary action
95
Protons + neutrons + electrons make ________
atoms
96
Atoms group together to make ________
molecules
97
Molecules group together to make _______
matter
98
Sometimes when two different types of molecules get together, they switch atoms around and make different molecules. This is called a __________
chemical reaction
99
When chemical reactions happen, _______ cannot be created or destroyed
atoms
100
__________ wrote the Atomic Theory of Matter in 1766
John Dalton
101
________ is anything that takes up space and has mass (weight).
Matter
102
Matter comes in three states—name them.
solid, liquid, and gas
103
The three states of matter are differentiated by the physical properties of ___________________
definite shape and volume
104
True or False: Water is found in all three states—ice, liquid water, and steam—over the normal temperature range
True
105
The special name for the point where matter goes from solid to a liquid _____________
melting point
106
The special name for the point where matter goes from liquid to a solid
Freezing point
107
The special name for the point where matter goes from gas to a liquid
Condensation point
108
The special name for the point where matter goes from liquid to a gas
Boiling point
109
The temperature of the freezing point = the temperature of the _______________
melting point
110
The temperature of the boiling point = the temperature of the _____________
condensation point
111
Boiling point of water = condensation point = what temperature in Fahrenheit and Celsius?
212˚F (100˚C)
112
The melting point of water = freezing point = what temperature in Fahrenheit and Celsius?
32˚F (0˚C)
113
True or False: Some matter does not fall completely into one of the three defined states
True
114
The molecules in a ________ are close together
solid
115
The molecules in a _______ do not move much, they vibrate slightly and have a fixed position relative to each other
solid
116
True or false: Solids are less dense than gases.
False. Solids are MORE dense than gases.
117
The amount of stuff in a given space
Density
118
_______ have a definite shape and a definite volume
Solids
119
Solids are more dense than liquids, with the important exception of _________
water
120
_______ is affected by the amount and type of molecules or elements present
Density (there are probably other things that could fit here too, but at the moment this section is about density)
121
Molecules stick together by sharing __________
electrons
122
Molecules in _____ are close together and don’t move much
solids
123
Molecules in liquids are farther apart and move more than in ________
solids
124
Molecules in ______ are not very close together—they move a lot
gases
125
The molecules in a ______ are close together but not as close as in a solid
liquid
126
The molecules in a liquid move around but not as much as in a _________
gas
127
_________ have a definite volume, but not a definite shape
Liquids
128
True or False: Different types of liquids can have different densities
True
129
True or False: Water is essential to life, as we know it
True
130
_______ bonds hold water molecules together
Hydrogen
131
Because ice is MORE or LESS dense than liquid water, the same number of molecules in ice has a GREATER or SMALLER volume than those molecules in liquid water
less dense / greater volume
132
Water can be separated into hydrogen and oxygen gases through a process called ______________
electrolysis
133
The molecules in a _____ have a lot of space between them
gas
134
The molecules in a ________ are fluid, move very fast, and mix freely
gas
135
______ do not have a definite volume or a definite shape
Gases
136
Gases are MORE or LESS dense than solids and liquids
less
137
Because gases are less dense than liquids, they will __________
float to the top and out of a liquid
138
True/False: Oxygen is essential to life
True
139
True or False: Air doesn't take up space
False. Air takes up space!
140
Air is 78% nitrogen and 21% oxygen. ________ is cycled between people, animals, and plants
Oxygen
141
True or False: Air is important for regulating the temperature on earth
True
142
True or false: In a chemical reaction, the molecules at the beginning are NOT the same as those at the end
True
143
True or false: In a chemical reaction, the atoms at the beginning are NOT the same as those at the end
False: The same atoms are there, but they are bonded differently
144
When there is a __________ change, the molecules present do not change
physical
145
In a chemical reaction, the starting molecules are called _____________
reactants
146
In a chemical reaction, the ending molecules are called ______________
products
147
What are three evidences of chemical change?
temperature change,
the formation of bubbles, or
a solid forming
148
Chemical reactions are written as equations
Answer
149
___________ reactions release heat
Exothermic
150
___________ reactions absorb heat
Endothermic
151
Acids taste __________
sour
152
Bases taste __________
bitter and feel slippery
153
________ tell if a solution is an acid, a base, or neutral
Indicators
154
In _______, the hydrogen atom comes off in a solution and leaves an electron
acids
155
In acids, the hydrogen atom comes off in a solution and leaves an electron. This is called a ___________.
dissociation reaction
156
In _______, the oxygen and hydrogen atoms come off in solution and take electrons
bases
157
In bases, the oxygen and hydrogen atoms come off in solution and take electrons. This is called a __________
dissociation reaction
158
acid + base = water + salt = ____________
an acid-base reaction
159
H without its electron (from an acid) and OH with an electron (from a base) makes _______
H2O
160
If an acid and a base solution are mixed, and the resulting solution is neutral, it is called a __________ reaction
neutralization
161
The____________ is used to measure the strength of an acid or a base
pH scale
162
The pH scale measures from ___ to ____
0 to 14
163
What number is neutral neutral on the pH scale?
7
164
A value less than 7 on the pH scale is a/an _________
acid
165
A value greater than 7 on the pH scale is a/an _________
base
166
In precipitation reactions, different ______ are mixed together and one of the products formed is a _____
LIQUIDS are mixed together / one of the products formed is a SOLID
167
______________________ reactions are the type of chemical reactions used to make bones, teeth, shells, and coral reefs
Precipitation
168
Combustion reactions must have ________________ as one of its reactants
oxygen gas
169
Are combustion reactions are exothermic or endothermic?
exothermic
170
What happens if oxygen gas is taken away from a fire?
The fire goes out and the reaction stops
171
Air is ____% nitrogen and ____% oxygen.
Air is 78% nitrogen and 21% oxygen.
