When does a change in energy occur?

1. In some physical changes, but not all.

2. In every physical change, but not in a chemical change.

3. In every chemical or physical change.

A substance with a pH of 9 ha

What produces magnetic fields? A) a built-up electric charge B) moving electric charges C) a wire wound around a bar magnet D) two electrical insulators connected together

A chemical reaction takes place in which energy is released. Arrange the reaction's characteristics in order from start to finish.

In a laboratory experiment, John uses mesh to seperate soil particles from water. Which technique of seperation is he using?

Methane gas (ch4), on complete combustion in air, produces: 1. co2 2. h2 3. h2o methane gas (ch4), on complete combustion in air, produces: 1. co2 2. h2 3. h2o 1 and 2 only 2 and 3 only 1 and 3 only all of 1 and 2 only none of

What can show the presence of carbon dioxide?

How does the shape of a structure affect its overall strength

Kim is doing an experiment with sound waves. She tested to see how quickly a sound wave could travel through three different materials: a metal pole, a helium balloon and a glass of water. She recorded her results.

Which of the following is an example of an electric force that occurs in atoms

5. What is another name for Newton's first law in your own words.