Select a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, just select one of them. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be lower. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be lower. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher. There was no difference in recovered and original mass, so there is no difference to account for.

It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.

Explanation:

If not all the water is evaporated from the sand so the recovered mass to be higher than the sand from which more water is evaporated because evaporation of little amount of water causes less decrease in the recovered mass as compared to that sand from which more water is evaporated so more decrease occur in the recovered mass.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

answer: mole of the gas

answer: mole of the gasexplanation: