Science Midterm Flashcards
(99 cards)
1
Q
matter
A
anything that has mass and takes up space.
2
Q
mass
A
amount of matter in an object
3
Q
What is the unit of mass
A
grams (g)
4
Q
weight
A
a measure of the gravitational forces on an object
5
Q
Can an objects weight change on the location of the object?
A
yes
6
Q
Does the mass of an object change based on its location?
A
no
7
Q
What instrument would be used to measure mass?
A
triple-beam balance
8
Q
What is the standard scientific unit for weight?
How else can it be represented?
A
standard- Newton (N)
also represented as pounds (lbs)
9
Q
What is the formula for volume?
A
V=lwh (length x width x height
10
Q
In what units is volume expressed?
A
Liters (L) or mL
11
Q
How is volume measured (what instruments)?
A
Graduated Cylinders or beakers
12
Q
What method can be used to determined the volume of an object?
A
Water displacement.
13
Q
Density
A
measure of the amount of mass in a given volume
14
Q
How does the density of an object change with the amount of the object that there?
A
It does not change.
15
Q
What is the formula for Density?
A
D=m/v
16
Q
physical property
A
a characteristic of a substance that can be observed and measured without changing the identity of the substance
17
Q
solubility
A
ability of a substance to dissolve in another substance
18
Q
Examples of common physical properties.
A
Density Solubility Electrical Conductivity Malleability Melting Point Boiling Point
19
Q
Ability of a substance to be rolled or pounded into various shapes
A
malleability
20
Q
Chemical Properties
A
substances ability to change into a new substance with different properties
21
Q
Can be observed only as the identity of a s subtance changes
A
Chemical properties
22
Q
examples of chemical properties
A
reactivity
flammability
23
Q
what is the difference between a physical property and a chemical property?
A
A physical property can be observed without changing the identity of a substance. A chemical property can be observed only by changing the identity of a substance.
24
Q
The characteristic properties of a substance do/do not depend on the size of the sample.
A
Do not.
25
Flammability is an example of a what property?
Chemical
26
Electrical conductivity is as example of a what property?
physical
27
Must new substances be formed when you observe a chemical property?
yes
28
Matter is lost when a candle is burned. T/F
False
29
physical change
change that affects one or more physcial property of a substance
30
Give examples of physical properties that can be changed.
appearance
shape
size
31
Give examples of physical changes.
```
stretching a rubber band
dissolving sugar in water
cutting hair
melting butter
bending a paper clip
crushing an aluminum can
cutting paper
```
32
chemical change
when one or more substances change into an entirely new substance with different properties, the process by which substances actually change into a new substance
33
Give an example of how chemical properties and chemical changes are not the same.
burning is a chemical change
| flammability is a chemical property
34
Give examples of how you can tell a chemical change has happened.
```
production of gas
production of odor
formation of a precipitate
change in color
change in energy (usually, painting something is a physical change but rusting is a chemical change)
```
35
law of conservation of mass
in ordinary chemical and physical changes, mass is not created or destroyed but isonly transformed into another substance
36
When water freezes in a glass, how does the amount of matter in the glass change?
it doe not change
37
smallest unit of an element that maintains the properties of that element
atoms
38
element
made up of one or more of the same kind of atom chemically combined
39
compound
made up of different kinds of atoms chemically combined
40
mixture
contains a variety of elements and compounds that are not chemically combined with each other
41
pure substance
a substance that has definite physical and chemical properties such as appearance, melting point, and reactivity
42
elements and compounds are examples of what?
pure substance
43
Can pure substances be formed or broken down by physical changes?
no
44
What is required to break bonds of elements?
chemical changes
45
How are elements classified?
metals
nonmetals
metalloids
46
What is shiny, conducts heat and electricity well, and can be shaped into thin sheets and wires?
metals
47
What is not shiny and do not conduct heat or electricity well?
nonmetals
48
What has some properties of both metals and nonmetals?
metalloids
49
How can compounds be classified?
pH
organic or inorganic
role in the body (lipids/proteins/nucleic acids, etc)
50
combination of two or more substances that are combined physically but not chemically, can be separated by physical changes
mixture
51
heterogeneous mixture
one that does not have a uniform composition
52
homogeneous mixture
uniform composition or structure throughout
53
suspension
type of heterogeneous mixture in which particles are too large to stay mixed without being stirred or shaken
54
colloids
mixture that falls between suspension and solution, particles are spread throughout a liquid or gas but are small and do not settle out quickly
eg: milk & gelatin
55
are colloids homogeneous or heterogeneous?
they look homogeneous but are considered heterogeneous
56
solution
homogeneous mixture, one substance is dissolved in another substance
57
solid
- substance that has a definite volume and shape
| - particles are close together and do not move freely, they vibrate but are fixed in place
58
liquid
- a substance that has definite volume but not a definite shape
- particles have more kinetic energy
59
gas
- substance without definite volume or shape
| - particles have the most kinetic energy of the three states
60
when a liquid becomes a gas at the liquids surface
evaporation (eg. puddle drying out)
61
condensation
gas becomes a liquid
62
a solid becomes a gas
sublimation
63
gas becomes a solid
deposition
64
liquid becomes a gas throughout
boiling
65
liquid becomes a solid
freezing
66
solid becomes a liquid
melting
67
T/F When the distance between gas particles increases, the volume of the gas increases
True
68
What happens when matter changes state?
Energy is gained and lost but the net energy is conserved. A substance must gain energy from the environment or lose energy to the environment but total amount of energy is conserved.
Mass is conserved
69
smallest particle into which an element can be divided and till be the same element
atom
70
Can you see an atom with a light microscope?
no
71
negatively charged particles
electrons
72
What was John Dalton's theory?
- all matter is made up of atoms
- atoms cannot be created, divided or destroyed
- all atoms of a certain element are identical
73
how do the ideas of John Dalton differ from those of Democritus and Aristotle?
Dalton's theory was based on evidence from experiments
74
What did JJ Thompson believe?
- atoms are made of even smaller particles
| - found particles within the atom that have a negative charge- became known as electrons
75
Ernest Rutherford
- experiment suggested that atoms have a nucleus
| - found that the nucleus is made up of positively charged particles and are called protons
76
Nucleus
small, dense center that has a positive charge and is surrounded by moving electrons
77
Niels Bohr
- observations led to a new theory of how electrons in a storm behave
- believed that electrons move around the nucleus in circular paths
78
What is the atomic theory?
- atoms are basic unit of matter and atoms of each element are unique
- atoms are made up of electrons and protons
- nucleus contains uncharged particles called neurons
- electrons do no move in circular paths around the nucleus but within an area around the nucleus called the electron cloud
79
James Chadwick
- discovered that the nucleus contains uncharged particles called neutrons
- electron cloud
80
what particles reside in the nucleus?
protons and neutrons
81
What charge is the nucleus
positive
82
How can you describe atoms?
atomic number
| mass number
83
number of PROTONS in the nucleus of an atoms
atomic number
84
number of PROTONS AND NEUTRONS in an atom's nucleus?
mass number
85
Isotopes
atoms of the same element that have different numbers of neutrons
86
Elements in the same ___ on the periodic table have the same number of valence electrons.
group
87
Properties of elements within a ___ on the periodic table change in a predictable way from one side of the table to the other.
period
88
Elements in the same ___ have similar properties.
group
89
rows on the periodic table are known as ___
periods
90
Each vertical column of elements from top to bottom on the periodic table is called a ___.
group
91
Another name for a group is a ___
family
92
What are valence electrons?
electrons found in the outermost portion of the electron cloud
93
Describe how valence electrons determine the reactivity of an element.
The more valence electrons, the less reactive the element is.
94
Each horizontal row of elements on the periodic table *from left to right" is called a ___
period
95
Explain how elements are arranged.
According to increasing atomic number.
96
Chemical symbol
abbreviation for the elements name
97
Average atomic mass
- weighted average of the masses of all the naturally occurring isotopes of that element
- number on the bottom of the square
98
Atomic number
- At the top of the square on the periodic table
- number of protons and neutrons
- all atoms of the same element have the same atomic number
99
What does the zigzag line on the periodic table represent?
separates the metals from the nonmetals
