waves - properties of waves 2 Flashcards
what happens when electromagnetic waves generated or absorbed?
changes happen in atoms or nuclei of atoms
what happens when we heat atoms?
electrons move from one energy level to a higher one. when returns to original level it generates electromagnetic waves
what is a electromagnetic wave generated?
a change to the nucleus e.g gamma rays rich men
what can emit gamma rays?
nucleus of radioactive atoms leaving it with less energy than it started with
when can electromagnetic waves emit and absorb?
over a wide frequency range from radio waves to gamma rays
what waves are hazardous to human body?
ultraviolet waves, x-rays and gamma rays
how is ultraviolet hazardous?
increase risk of skin cancer and causes skin to age prematurely
how are x-rays and gamma rays hazardous?
they are ionising radiation meaning they can knock off electrons off atoms when absorbed. they can cause mutations to DNA, increasing risk of cancer
what does the damage of x-rays and gamma rays depend on?
type and dose
what is dose of ionising radiation measure in?
sieverts (Sv)
millisieverts (mSv)
how are radio waves produced?
when electrons oscillate in electrical circuits (move back and forward)
what happens when circuit absorb radio waves ?
causes electrons in circuit to oscillate creating an alternating current with same frequency as radio waves
