A ring made of gold is heated and then hammered into a flat, coin-like shape. Is this a physical change? Explain.

Temperature affects: metabolic activity the quality of the air the amount of sunlight in an ecosystem

A student claims that since the three phases have different amounts of energy, molecules in substances gain or lose energy only during phase transitions. Explain what is wrong with this student's reasoning.

Which of the following would increase the strength of an electromagnet?

What's a good problem statement for a project on hair ties?

Which source would be the least reliable?

X-rays UV light waves Sound waves Earthquake waves. All of these have which characteristic in common?

V=345m/s, 7210Hz, X=?

As a mercury atom absorbs a photon of energy, an electron in the atom changes from energy level d to energy level e. Determine the energy of the absorbed photon in electronvolts.

During an exothermic reaction, the energy given off comes from atoms being consumed mass being burned into energy the breaking and forming of bonds mass being created

Can electrostatic attract both pull and pull?