Which is true about all particles of matter?
They are made of molecules.
They are in constant motion.
They are solid.
They are made of cells.
2. They are in constant motion
When an ice cube melts over time, the particles of the ice cube _________.
Loses kinetic energy
Gains kinetic energy
Loses potential energy
Gains potential energy
2. Gains kinetic energy
What happens to the particles of matter when a chemical reaction takes place?
They burn
They become less
They rearrange
They become more
3. rearrange
During an exothermic reaction, heat ____________
Is Released
Is Absorbed
Is constant
Is Not needed.
1. is released
Kinetic energy is possessed by objects in/at/on
Rest
Motion
Earth
air
2. In motion
When a solid substance melts, it _____ energy.
absorbs/gains
releases/loses
Produces
creates
1. absorbs/gains
Which is not an example of a chemical change?
Water evaporates during boiling
Baking of bread
Browning of a sliced apple
Rusting of an iron nail
1. water evaporates when boiling
Which shows a sign of an endothermic reaction?
The container where the reaction happens feels cold
The container where the reaction happens feels warm/hot
The container where the reaction happens remains the same
The container where the reaction happens changes into a new substance
number 1
The average kinetic energy of particles of a substance is called ___________.
Thermal energy
Heat energy
Temperature
warmth
3. Temperature
When a liquid substance freezes, it _____ energy.
absorbs/gains
releases/loses
Produces
creates
2. releases/loses
Which is not a physical change?
Peeling of paint on a wall
Statue of liberty turning green
Boiling of water
Crushing chalk into powder
2. statue of liberty turning green
Which shows balanced forces?
1. a boy riding his bike
2. a bird flying
3. a book on the chair
4. the wind blowing
3. a book on the chair
The total kinetic energy of all the particles of a substance is called.
Thermal energy
Heat energy
Temperature
warmth
1. Thermal energy
When a liquid substance turns into vapor, it ________ energy.
absorbs/gains
releases/loses
Produces
creates
1. absorbs/gains
Which are signs of chemical reactions? Choose all that apply.
A new substance is formed
Change in shape
Gas or smoke is produces
Heat is produced
Heat is absorbed
Sound is produced
all except number 2
Which shows unbalanced forces
1. a leaf on a branch
2. a cup on a saucer
3. a waterfall
4. a cloud
3. a waterfall
When a substance gains thermal energy its kinetic energy _______
Increases
Decreases
Remains the same
Is lost
1. Increases
When a chemical reaction happens, ______ is released or absorbed.
Matter
Energy
Light
air
2. energy
During an endothermic reaction, heat energy _______
Is Released
Is Absorbed
Is constant
Is Not needed.
2. Is absorbed
What forces causes a team to win over another team in a tug of war game?
1. balanced
2. unbalanced
unbalanced