If, at standard temperature and pressure (STP), one mol of gas occupies 22.4L, how many moles are there in 16.0L of the gas at STP?

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.

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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.  

false it is never safe to stand on the top step of a ladder provided it is braced properly.

i don't think it is possible.