Atoms are made up of protons , electrons and neutrons ..,, Atoms of the same element with different number of neutrons are called isotopes. Saying that substance “contains only one type of atom “ really means that it contains only atoms that all have the same number of protons .
To calculate the number of moles, simply take the ratio of mass and molar mass. The molar mass of Iron (Fe) is equal to 55.85 g/mol.Therefore the total number of moles is:
moles Fe = 25.7 g / (55.85 g / mol)
moles Fe = 0.46 mole
Answer:
b 13kg/m³ is the answer to this question
Answer:
You may be referring to the gas that makes up 21% of the earth's atmosphere, which is oxygen.
Explanation:
According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent
Oxygen — 21 percent
Argon — 0.93 percent
Carbon dioxide — 0.04 percent
(Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor)
