Measurements
Measurements:
a). provide scientists with a quantity
b) require tools
c) both a & b
d). none of the above
ANSWER: C--both a & b
Pressure is:
a) a measure of the ability to do work or generate heat
b) the amount of space that matter occupies
c). the amount of matter per unit of volume
d). the amount of force exerted per unit area
ANSWER: D
P=F/A
*Scientists use the following units to measure pressure: Pascals, atmospheres, torrs, millimeters of mercury or pounds per square inch
Ricky likes to spread lots and lots of hair gel in his hair every morning. Ricky knows from his chemistry class that a gel:
a). consists of liquids spread throughout other liquids
b) is a colloidal suspension of liquid or fine solid particles in a gas
c) consists of gases finely spread throughout liquids or solids
d). consists of liquids spread throughout a solid
ANSWER: D
a=emulsion
b=aerosols
c=foams
pg 26
Which process is primarily a physical change?
A. A seed growing
B. Dough rising
C. Dynamite exploding
D. Glass shattering
ANSWER: D-glass shattering
Example: tearing or cutting a piece of paper. The paper is in smaller pieces, but the chemical makeup of the paper has not changed
An example of vaporization is:
a). ice melting
b) water boiling
c) frost forming on a car window
d) ice cream melting
ANSWER: b
Vaporization is a change in state from a liquid to a gas
Bonus!
What are the two main types of vaporization?
pg 33
Evaporation and Boiling
Accuracy:
a). refers to the ability to take the same measurement and get the same result over and over
b). the measure of the quantity of material in a substance
c). refers to how close a measured value is to the true measurement
d). measures the pull of gravity between an object and the earth
ANSWER: C--refers to how close a measured value is to the true measurement
a=precision
b=mass
d=weight
pg 9 & 10
If Travis Kelce weighs 250 lbs (pounds), how would this be written in scientific notation?
a) 25.0 x 10^1 lbs
b) 250 x 10^0 lbs
c) 2.50 x 10^2 lbs
BONUS POINTS:
WHAT IS THE METRIC UNIT FOR MASS?
c) 2.50 x 10^2 lbs
BONUS POINTS: gram
True or False:
A compound is a pure substance?
ANSWER: True
pg 26
At a low temperature, (0 degrees Celsius or below), water molecules have a:
a). high energy
b) low energy
c). no energy
ANSWER: b--low energy
At low temperatures, (0 degrees Celsius or below), water molecules have low energy, so the water becomes a solid. The most common solid form of water is ice.
pg 32
Liquid forms on cold cans of soda after they are taken out of the refrigerator through the process of condensation. What is this liquid formed from?
A. Solid dust
B. Suspended water droplets
C. Tiny ice particles
D. Water vapor
D. Water vapor
Condensation: A change of state from a gas to a liquid
Taylor Swift wants to determine the volume of her solid rectangular eye shadow case. Taylor's eye shadow case is 2cm x 1cm x 4cm. What is the volume of Taylor Swift's eye shadow case?
ANSWER: V=8cm3
Volume= l x w x h
*When you multiply measurements togethter, their units are also multiplied
*What tool do you use to measure the volume of a liquid? ANSWER: A graduated cylinder
True or False:
A mixture can be classified as homogeneous or heterogeneous
True
Fog is an example of a:
a) Homogenous mixture
b) Heterogeneous mixture
c) Colloid mixture
d) Alloy
c). Colloid mixture
*A mixture in which minute particles are spread evenly throughout another substance (whip cream, mayonnaise, milk)
*Sols are colloids made of fine solid particles in a liquid or another solid
Liquid sols: paint, a muddy river and sewage
Solid sols: pearls, colored glass, and pigmented plastics
Kenzi conducts an experiment to determine whether sugar dissolves faster in hot water or cold water. What is the dependent variable in her experiment?
a) The temperature of the water
b) The amount of water in the cups
c). The rate at which the sugar dissolves
D. The brand of sugar used
Answer: C
Chlorophyll is the chemical compound that gives leaves their green color. One reason leaves turn from green to brown in autumn is that as temperatures decrease, plants produce less chlorophyll. Which process causes leaves to appear green?
a) a chemical reaction
b) deposition
c) a physical change
d) The Tyndall effect
ANSWER: a chemical reaction
At a high temperature, particles of matter move:
a) slow
b) fast
c) not at all
BONUS: What type of energy does temperature measure?
ANSWER: b--fast
Temperature is the measure of the average kinetic energy (energy of motion) of particles of matter. A higher temperature means that there is more energy, so particles are able to move faster.
What do scientists usually measure degrees in? ANSWER: Celsius (C) or Kelvin (K)
Allotropes contain how many types of atoms?
a) 1
b) 2
c) 3
d) 12
ANSWER: a
Allotropes are different forms of the same element in the same physical state of matter. Allotropes contain only one type of atom, however the way that the atoms are arranged is different.
*Each allotrope is a pure form of that element
*Two solid allotropes of carbon are graphite (pencil lead) and diamond. They are both forms of carbon
True or False:
Water has a lower viscosity than honey
ANSWER: True
Viscosity is a property of liquids that describes the "thickness" of a material. The less viscous a fluid, the ore easily it flows.
Which process is an example of condensation?
a). Water vapor changing to ice
b) Dry ice changing to gaseous carbon dioxide
c). Hydrochorlic acid changing to hydrogen chloride gas
d). Nitrogen gas changing to liquid nitrogen
ANSWER: D
Condensation is a change of state from a gas to a liquid
pg 34
An X-ray is an example of what type of energy?
a). mechanical energy
b) nuclear energy
c) radiant energy
d) thermal energy
ANSWER: c
Radiant energy is assosciated with electromagnetic energy that travels in waves. Examples are: visible, ultraviolet and infrared light, microwaves, x-rays, gamma rays and radio waves
pg 38
Two liquids, A and B, have densities 0.75 grams per milliliter and 1.14 grams per milliliter, respectively.
When both liquids are poured into a container, one liquid floats on top of the other. Which liquid is on top?
ANSWER: Liquid A. (0.75 grams per milliliter)
What is the mass of a 15 cm cube of iron if the density of iron is 7.87 gm/cm3?
ANSWER: 12, 561 gm or 26.56 kg
D= Mass (M)/Volume (V)
V= l x w x h
Which of the following are pure substances?
a) oxygen
b) asphalt
c) flowers
d) silver
a) oxygen
d) silver
Rose gold, which is often used to make jewelry, is an alloy of gold, copper, and silver. The copper gives the gold its reddish color. What is true of rose gold?
A. It is mixed evenly throughout
B. It cannot be broken down by normal chemical or physical means
C. It does not conduct electricity
D. It is a pure ternary compound
ANSWER: A
An alloy is a homogenous mixture of metals (examples: brass, bronze)
Bonus!
What is a homogenous mixture of a liquid or a gas?
pg 24
All of the following are examples of chemical changes except:
a). iron rusting
b). gasoline burning
c) baking a cake
d). coffee dripping
ANSWER: d--coffee dripping