Answer:
38.541 × 10¹⁹ formula units
Explanation:
Given data:
Mass of chromium sulfate = 0.25 g
Formula units in 0.25 g = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ formula units of water
Number of moles of chromium sulfate = Mass / molar mass
Number of moles of chromium sulfate = 0.25 g/ 392.16 g/ mol
Number of moles of chromium sulfate = 6.4 × 10⁻⁴ moles
Number of formula units:
1 mole = 6.022 × 10²³ formula units
6.4 × 10⁻⁴ moles × 6.022 × 10²³ formula units / 1 mol
38.541 × 10¹⁹ formula units
60 elements! I don't exactly know every element known, so if you are asking that, please tell us, but what I do know is that there were 60 elements in the periodic table by 1860.
Answer:
one in a 2s orbital
Explanation:
Because of the peak near the nucleus in the 2s curve there is a higher probability of finding a 2s within 4 Å of the nucleus. In a multi-electron atom an electron in a 2s orbital will have a lower energy than one in a 2p orbital
