5.00 of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 128./gmol, is burned completely in excess oxygen, and the mass of the products carefully measured: product mass carbon dioxide 17.19g water 2.81g Use this information to find the molecular formula of X.

C10H10

Explanation:

Use a balanced equation to determined quantity of carbon and hydrogen. Then use simple division to determine the empirical formula before the molecula formula

the temperature of the gas, in k, not celsius.

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.