What are not true about pure substances?

Wavelength,frequency,and energy are related.what happens to a wave as it’s wavelength gets shorter?

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?

Two technicians are discussing a starter that clicks repeatedly when the key is turned to the crank position. technician a says the solenoid hold-in winding is open. technician b says the solenoid pull-in winding is open. who is correct?