Describe and Classify
What is matter?
Anything that has mass and takes up space.
What is a mixture?
a mixture is made of two or more substances combine together, but not chemically bonded.
What is weight? Give an example of a location where my weight would change without changing my mass.
The measure of the force of gravity on an object.
Example: Jupiter, the moon, outer space.
What is a physical Change? Give an example.
A change in which you can alter the form or appearance of matter without changing it into something else.
If I break glass, I've changed the appearance, but it is still glass. Other examples may also work.
When warm and cold air meet, what happens. and how does it relate to density?
Warm air expands. Cold air contracts, Because of this, warm air has less density than cold air. This causes warm air to rise above cold air.
What is a chemical property? Give an example.
A Chemical property is a characteristic that can only be observed by combining or breaking apart substances.
Examples might include: Rust, or photosynthesis.
What is a solution? Give an example.
A solution is a mixture of two substances. It contains at least one liquid.
Salt water is a good example.
What is SI? Give an example of one of it's units
SI, the International System of Units, is a unit standardization used by scientists.
Examples: kg, mL, g, L
What is a chemical change. Give an example.
A chemical change is a change in matter that produces one or more new substances.
When yeast reacts with sugar, while making bread, it produced carbon dioxide, which makes the bread rise. Because there is a change in substances and we make something new, this is a chemical change. Other examples will also work.
How might a scientist use density with an unknown substance?
A scientist can find the density of an unknown substance and compare it to known density values, until they are able to figure out what the substance is based on it's density.
What is a Physical property. Give two examples.
A Physical property can be observed without changing the matter into something else.
Examples include: shape, size, hardness, etc.
What is distillation?
If I weigh 50 kg, find my weight in pounds.
110 lbs.
Why? Because the conversion factor between kg and lbs is 2.2. That is, there are 2.2 lbs in every kilogram.
What is the law of conservation of mass?
It states that matter is not created or destroyed, even when an substance undergoes physical or chemical changes.
What is the difference between thermal energy and temperature?
Thermal energy is the total energy of all the particles in a substance, Temperature, on the other hand, measures the motion of each individual particle.
What is an atom, and how does it relate to molecules?
And atom is the basic unit from which all matter is made. It relates to a molecule, because molecules are arrangements of atoms held together by a chemical bond.
What is the difference between a homogeneous and a heterogeneous mixture? Give an example of each.
A homogeneous mixture is hard to separate. It may all look the same (think of a cake mix). A homogeneous mixture has pieces that are easily identifiable and different, so it's easier to separate (think of a bowl of mixed nuts).
What two other measurements do you need to find an object's density? How is the equation written? Define each measurement.
Density = Mass / Volume
Density is the measure of the mass of a material in a given volume.
Mass is the amount of matter in an object.
Volume is the amount of space an object takes up.
When matter changes, energy is generally released or absorbed. What is the release and absorption called?
Endothermic changes absorb energy.
Exothermic changes release energy.
I have 3 molecules:
H2O
O2
NaCl
What makes the O2 different?
While all three are molecules, the O2 is not a compound.
What is a substance and how does it relate to compounds and elements?
an element is made up of only one type of atom. While an element can be a substance, it is not the only substance. Substances are a single type of matter, with a specific composition. This could be an element, but it could be a compound like Salt, where the Sodium and Chloride (elements) are arranged specifically.
Tell 2 different ways to separate a solution.
Magnetic attraction, distillation, evaporation, filtration
An ice cube has a mass of 4 kg, and a volume of 3.5 mL. Find the density, and give me one factor that might impact the density of the cube. Why? (Calculator is allowed)
Density is 1.14
Temperature impacts density. Because water expands when frozen and contracts when it gets warmer, until it becomes a gas, when it expands again.
Please note: this is not the actual density of an ice cube.
If you dissolve sugar into water, is this a physical or chemical change. Explain.
Physical. Both substances are still the same in this solution. Granted, it's a homogeneous mixture, but you can evaporate out the water to get your sugar back, and it will still be sugar. Nothing has changed into something new.
The force of gravity on the moon is only 16.6% that of gravity's force on earth. If a person weighed 65 kg on earth, how much would they weigh on the moon?
Daily double: Double the points if you can give each weight in pounds.
The same person would weigh 10.79 kg on the moon, because 65 x .116 (percentage converted to a decimal), gives you this number.
Daily double: On earth, they weigh 143 lbs. On the moon, it's 23.7 lbs