Which of the following samples will have the lowest pressure if they are all at the same temperature and in identical containers (same volume)? a. 15 g Ne
b. 15 g
c. 15 g Kr
d. 15 g CO2
e. 15gF2
f. All of these samples will have the same pressure.

c. 15 g Kr

Explanation:

The amount of a gas (Moles) is directely proportional to its pressure. That means the higher amount of moles, the highest pressure and vice versa.

Using molar mass of the compounds (Ne=20.2g/mol, Ar = 39.9g/mol, Kr = 83.8g/mol, CO₂ = 44 g/mol and F₂ = 38.0g/mol), moles of 15.0g of each gas are:

Ne = 15g ₓ (1mol / 20.2g) = 0.74 moles of Ne

Ar = 15g ₓ (1mol / 39.9g) = 0.38 moles of Ar

Kr = 15g ₓ (1mol / 83.8g) = 0.18 moles of Kr

CO₂ = 15g ₓ (1mol / 44g) = 0.34 moles of CO₂

F₂ = 15g ₓ (1mol / 38g) = 0.39 moles of F₂

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; talc and gypsum;