Matter
All matter is either a mixture or a ____
pure substance
Name four kinds of energy we've learned about. (We've learned 7)
kinetic (KE)
potential (PE)
mechanical (ME)
electrical
light (electromagnetic, EM)
sound
nuclear
protons, electrons, neutrons
Which part of the atom moves around to cause electricity?
electrons
What is the name for what a wave travels through?
medium
There are two kinds of pure substances. What are they?
elements and compounds
What two properties affect how much KE a ball has when it hits something?
Imagine an atom that has 14 protons, 19 neutrons, and 17 electrons. It is in group 4 and period 3. What is this atom's atomic number?
14 (atomic number = number of protons)
Which type of static electric charge transfer best explains why putting on a sweater can cause your hair to stand up?
friction
Which state of matter does sound travel fastest through?
solid
What makes a homogeneous mixture different from a heterogeneous mixture?
Homogeneous mixtures have uniform distribution: every part of the mixture has the same amount of each ingredient.
Which type of heat transfer occurs due to the collision of particles?
conduction
Atoms in the same ___ have similar properties.
group OR column
Around which part of a magnet is the magnetic force the strongest?
closest to the poles
Which word correctly completes this sentence? (There is more than one correct answer.)
"The more energy a wave carries, the greater the wave's __ will be."
amplitude OR frequency
What makes a physical change different from a chemical change?
A physical change does not produce a new substance. A chemical change does.
In which state of matter can convection NOT happen?
solids (convection only happens in liquids and gases)
In a chemical reaction, what are the substances on the left side of the arrow called?
(example: Na + Cl --> NaCl )
reactants
more current
OR
more wire turns
OR
larger iron core
Which part of the EM spectrum has the highest frequency?
gamma rays
Name three signs that a chemical change has happened. (We've learned 7)
an odor is produced
a gas is produced (smoke, bubbles)
change in color
change in energy (heat or light)
a precipitate is formed
a new substance is formed
chemical bonds are made or broken
You throw a ball up in the air. Before it falls back down, it stops. You gave the ball a lot of KE when you threw it. Where did that KE go when the ball stopped?
it turned into PE
Why do some atoms make chemical bonds but others don't?
atoms will gain and lose valence electrons until their outermost energy level is stable
What type of energy transformation happens in an electric generator?
ME (or KE) is transformed into electrical energy
What causes light to refract when it passes through something like a lens?
Waves change speed when they go from one medium to another. This makes them bend (change direction).