วิทยาศาสตร์กายภาพ

Which Statement describes a difference between static electricity and electric current?

• Only Electric current involves energy

• Only electric current involves the movement of electrons

• Only static electricity involves sudden electric discharges

• Only static electricity involves negative and positive charges

Which of these will the south pole of a bar magnet repel?

• paper clip

• an iron nail

• the north pole of another magnet

• the south pole of another magnet

Which substances does not have a fixed volume or a fixed shape?

• ice in a freezer

• water in a lake

• water vapor in air

• snow in a snowman

Which is a chemical property?

• whether a substance folds

• Whether a substance dissolves

• Whether a substance reacts with oxygen

• whether a substances changes from a liquid to a gas

Which of these are physical changes? Select two answers.

• a nail rusts

• a twig burns

• a ruler breaks

• a sugar cube dissolves

Which of these is a way to make an electromagnet stronger?

• putting a switch in the electrical circuit

• replacing the iron core with a copper core

• replacing the copper wire with a plastic wire

• wrapping the wire around and iron core MORE times

A student designs an electric circuit with a fan. What happens at the fan?

• electric current is turned on and off

• Electric current creates a positive charge.

• Electrical energy is supplied to the circuit

• Electrical energy is changed into another form of energy

Which are examples of chemical change? Select THREE answers.

• An egg is cooked

• water in a pan boils away

• A sliver quarter tarnishes

• Leaves in a compost pile rot

• Sugar dissolves in water

Which of these is a chemical property?

• whether a substance folds

• whether a substances dissolves

• whether a substance reacts with oxygen

• Whether a substance changes from a liquid to a gas

A student replaces the switch in an electric circuit with an object A light bulb un the circuit does not light up. What can the student conclude about the object?

• it is too large

• It is an insulator

• it is a conductor

• It is made of metal