How many atoms are in 490 moles of barium?

2.95 * 10^23 atoms

Explanation:

The number of atoms in a mole is always equal to Avogadro's constant, which is 6.02214076×10²³ mol⁻¹.

To find the number of atoms in 0.490 moles of barium, multiply it with Avogadro's constant:

0.490 mol * 6.02214076×10²³ mol⁻¹ ≈ 2.9508 * 10^23

Convert to SigFigs (if necessary):

2.95 * 10^23

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.