From the list below, determine which properties are for compounds. i. it takes a large amount of energy to separates the elements of a compound. ii. the proportions of the elements in a compound are always fixed. iii. it is easy to separate the elements of a compound. iv. the elements/components of a compound do not retain their individual properties.

helloi think dog cat bunny dog cat bunny dog cat bunny

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.