If you poured three liquids into a beaker, how could you tell which one is the densest liquid?

The liquid that settles to the bottom is the densest liquid

In science, what is a scientific theory?

an explanation for many hypotheses and observations

At higher temperatures

particles in an object move faster

What is the most important factor in determining how an atom will bond?

the number of electrons in the outermost energy level

How does a physical change differ from a chemical change?

In a physical change what it is, is unchanged

What can group numbers on the periodic table help you determine?

the number of valence electrons

Observing them produces new materials

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Science Review

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Review material for 1st semester BMMS

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Questions 96

Answers

1
Compounds can be broken down only by chemical means.
True
False
2
a physical change?
changes the substance totally
It only changes how it looks
It combines and forms new substances
3
What are the left-to-right rows on the periodic table
properties
families
periods
4
What element makes up about 20% of the air we breathe?
oxygen
nitrogen
bromine
5
Which of the following occurs when a gas becomes a liquid?
the particles lose energy
The particles clump together
The particles create energy
6
Metals?
left side
Right side
touching staircase line
7
If you poured three liquids into a beaker, how could you tell which one is the densest liquid?
The liquid that settles to the bottom is the densest liquid
The liquid with the deep red color is the densest liquid
The liquid that is floating on top is the densest liquid
8
In science, what is a scientific theory?
an explanation for many hypotheses and observations
the first idea to explain an observation
an experiment
9
During physical changes, matter only changes
if it burns
what it is
what it looks like
10
How would you describe the nucleus?
large, positively charged
dense, positively charged
tiny, negatively charged
11
An atom of carbon with 6 protons, 6 electrons and 6 neutrons would have a mass number of
6
18
12
12
who was the first person to relate atoms to elements
Dalton
Rutherford
Bohr
13
At higher temperatures
a gas contracts
gas particles bump into walls less often
particles in an object move faster
14
Gas to Liquid
condensation
evaporation
freezing
15
no definite shape or volume
gas
solid
liquid
16
One way to test pH is to use a strip of paper that has several
acids
hydronium ions
indicators
17
What must be done for a chemical equation to be balanced?
All molecules must be counted
All atoms must be counted
All chemicals must be equal
18
At the end of an experiment, what must you draw?
a conclusion
a bar graph
a picture
19
In a graduated cylinder containing several liquid layers, the least dense liquid is found
In the middle layer
In the lightest colored layer
Floating at the top
20
Hypotonic solution results in a net gain of water from the cell
False
True
21
What is the most important factor in determining how an atom will bond?
the number of neutrons
the number of electrons in the outermost energy level
the number of protons
22
What do atoms gain, lose, or share when they bond?
neutrons
electrons
protons
23
The scientific process begins with asking questions and
planning experiments
making observations
reading background
24
How does a physical change differ from a chemical change?
In a physical change what it is, is unchanged
In a physical change new materials are produced
In a physical change new volumes are created
25
Which of the following chemical equations is balanced?
3Ca + 2O2 ® 5CaO2
3Ca +O2 ® 3CaO2
Ca +O2 ® CaO2
26
The elements to the right of the zig zag line on the periodic table are called
nonmetals
metals
metalloids
27
Melting crayons is an example of a
chemical property
physical change
physical property
28
How did Mendeleev group elements?
by appearance
by increasing atomic mass
by density
29
Could use a magnet to seperate
atoms
certain mixtures
compounds
30
Which of the following will NOT increase the rate of a chemical reaction?
adding a catalyst
adding an inhibitor
increasing the concentration of reactants
31
Acids have a
sour taste
bitter taste
slippery feel
32
What can group numbers on the periodic table help you determine?
the number of electrons
the number of valence electrons
the number of protons
33
When a base is added to red litmus paper, the indicator turns
blue
red
purple
34
What is necessary for substances to burn?
hydrogen
helium
oxygen
35
Which of the following represents the number of protons in an atom?
covalent number
atomic number
proton number
36
bonding between two nonmetals?
metallic bonding
covalent bonding
chemical bonding
37
Which of the following has the least mass in an atom?
nucleus
neutron
electron
38
A chemical change?
They result in changes of state
Observing them produces new materials
changes color
39
Conduction
heat rises cold sinks
heat transfer by touching
transfer in waves
40
A neutral solution has a pH of
7
11
3
41
Boiling pt, melting pt, and density are some of an element's
nonreactive properties
chemical properties
physical properties
42
Where are electrons likely found?
mixed throughout an atom
electron clouds
the nucleus
43
Convection
heat rises cold sinks
heat transfer in waves
heat trnasfer by touching
44
What are the two main branches of physical science?
chemistry and physics
chemistry and biology
biology and physics
45
What is the joining of atoms to form new substances?
chemical bonding
joining chemicals
bonding atoms
46
What are the only parts of an atom that make chemical bonds?
valence electrons
protons in the nucleus
neutrons in the nucleus
47
Liquid to solid
melting
freezing
sublimation
48
Ionized gas super heated
supragas
hot atoms
plasma
49
Density
D= M * V
is a chemical property
D=M/V
50
What is the basic unit of length that a scientist is likely to use?
meter
foot
micrometer
51
In Thomson's "plum pudding model" of the atom, the plums represent
protons
electrons
neutrons
52
Solid to gas
Sublimation
condensation
Evaporation
53
Weight and mass are the same thing
False
True
54
What are charged particles that form when atoms gain or lose electrons
atomic ions
ions
particle atoms
55
What is a pure substance made of one type of atom?
compound
mixture
element
56
At the end of an investigation what should you do if your results don't support your hypothesis
repeat your investigation, and then change your hypothesis
change the topic you are studying
buy new measurement tools
57
Proton
electron
proton
neutron
58
Which of the following is a good safety rule to follow?
read lab instructions,but change them if you want to
take shortcuts if there is no danger
pay attention to safety information and safety symbols
59
What has mass and takes of space?
weight
matter
space
60
This substance has a bitter taste and slippery feel
organic compound
base
acid
61
What did Bohr, Democritus, Thomson, Dalton and Rutherford all have in common?
They each developed ideas about atoms
The each identified new electron clouds
They each identified the electromagnetic force of atoms
62
What do foods that taste sour usually contain?
acid
indicator
base
63
Who design the model of the atom where eletrons are in discrete orbits
Dalton
Bohr
Hemmingway
64
What is matter?
the "stuff" that is light enough to float
the "stuff" that everything is made of
the ability to do work
65
A substance that is rated 7 on the pH scale is considered
basic
neutral
weak
66
If hydrogen-1 has 1 proton how many protons does hydrogen-2 have?
3
1
2
67
The vertical column of elements on the periodic table is called a
period
group
atomic mass
68
Definite volume no definite shape
liquid
gas
solid
69
What happens in an endothermic reaction?
energy is created
energy is taken in
energy is released
70
What happens when a liquid becomes a gas?
The particles move farther apart
The particles move closer together
The particles give off energy
71
Radiation
heat transfer in waves
heat rises cold sinks
heat trnasfer by touching
72
Why does the law of conservation of mass dictate that chemical equations be balanced?
because elements are classified by weight
because chemical formulas are written from left to right
because atoms are never gained or lost in a chemicalreaction
73
Why should you NEVER taste or touch an unknown acid?
It could be slippery
It could be corrosive
It could smell bad
74
What is the charge of an aluminum ion that has 13 protons and 10 electrons?
2+
3+
1+
75
The smallest particle into which an element can be divided and still be the same substance is a
electon
atom
nucleus
76
pH higher than 7
acid
base
neutral
77
What chemical property is responsible for iron rusting?
electricity
flammability
reactions with oxygen and water
78
How can you tell that baking a cake produces a chemical change?
It produces changes of state in the ingredients
It combines the ingredients to form new substances
It causes changes in color
79
Bases have a
slippery feel
sour taste
sweet taste
80
definite shape and volume
solid
liquid`
gas
81
Why don't noble gases normally form chemical bonds?
They have a full outermost energy level
They have 2 valence electrons
They have an empty outer level
82
Most of the elements in the periodic table are
gases
metals
metalloids
83
How many carbon atoms are in this glucose molecule? C₆H₁₂O₆
twelve
three
six
84
Which of the following is a chemical property?
boiling point
reactivity with acid
density
85
How many sodium atoms are present in this molecule? 7Na₃PO₄
3
7
21
86
If a chemical symbol in a chemical formula has no subscript, it means
the chemical is listed last in the formula.
the element has no charge.
only one atoms of the element is in the molecule.
87
According to Rutherford, what was in the center of an atom?
a nucleus
a proton
an electron
88
pH lower than 7
base
acid
neutral
89
Which of the following properties of metals means that it can be drawn into wires?
electrical conductivity
malleability
ductility
90
Molecules stop moving
freezing
absolute zero
0 degrees
91
An isotonic solution results in no net charge in the cell
True
False
92
Made or more than one type of atom chemically combined
compounds
mixtures
elements
93
The amount of space something takes up
mass
volume
distance
94
How many atoms are represented in the formula CaCO_3?
five
three
four
95
How can a compound be broken down?
by physical changes
by crushing
by chemical changes
96
How can organizing data into tables, graphs help scientists analyze their data?
by adding color to their website
by making relationships easier to see
by speeding up the collection of data

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