Which statement about a physical and chemical change is true? Question 5 options:

If NO change in color is visible in a process, it must be a chemical change

if NO change in state of matter occurs in a process, it must be a physical change

A change in state of matter always indicates a chemical change

A change in color often occurs during a chemical change

The rules of engagement (roe) working group is often used to (select all that apply.)

Avariable that is not being directly tested during an experiment should be

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.