Giselle is working with a chemical substance in a laboratory. she observes that when the chemical is heated, it gives off a gas. she assumes that the gas is oxygen but decides to test this assumption to verify it. which type of scientific knowledge is giselle’s assumption? a. fact b. hypothesis c. law d. observation e. theory

What is the specific heat of a substance that absorbs 2.5×10^3 joules of heat when a sample of 1.0 ×10^4g of the substance increases in temperature from 10°c to 70°c?

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

An object becomes electrically charged when: electrons are created in it electrons from it are destroyed electrons are transferred to it protons from it are destroyed protons are created in it