Which of the following is a reason models have limitations?

What is the smallest unit of an element that can still be classified as an element called?

Particles in a substance are constantly in motion. The more energy the particles contain, the faster they move about. In which state of matter do the particles have the most energy?

A change of state may happen when energy as heat is transferred to or from a substance. Which change of state could occur as energy is added to a substance?

A scientific _______________ is a statement that describes what scientists expect to happen every time under a particular set of conditions.

Angelique wanted to find out what shampoo made her hair the shiniest. Everyday she washed her hair with different shampoos and then rated how shiny her hair was, on a scale from 1-10. She used Garnier Fructis, Suave, Herbal Essence, and just water. What is the independent variable?