Which are potential source's of error in the experiment check all that apply

estimating the mass of the sample to the nearest tenth of a gram

estimating the thickness of the foam cups

the position of the cups of sand and water under the heat lamp

the brand of light bulb used for the heat lamp the air temperature outside the lab

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.