Acompound composed of two oppositely charged elements.

The blackbody curve for a star name zeta is shown below. what is the peak wavelength for this star ?

Which of the following units is not an official si unit? mole liter kilogram ampere

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.