D - density: 0.5 g/mL
m - mass: 500g
V - volume: ???
________
d = m/V
V = m/d
V = 500/0,5
V = 1000 mL = 1 L
:)
Answer:
Two electrons
Explanation:
According to the octet rule, atoms must bond to each other, sharing electrons among themselves in an attempt to complete their valence shell (last layer of the electrosphere). In other words, an atom becomes stable when it has 8 electrons in its valence shell.
Oxygen atoms have six electrons in their valence shell, so to achieve the stability suggested by the octet rule (eight electrons), these atoms share two electrons, forming one oxygen gas (O₂) molecule.
142 g ---------------- 6.02 x 10²³ molecules
0.920g g ------------ ( molecules )
molecules = 0.920 x ( 6.02 x 10²³ ) / 142
molecules = 5.53 x 10²³ / 142
= 3.89 x 10²¹ molecules
1 molecule P2O5 -------------------------- 7 atoms
3.89 x 10²¹ molecules -------------------- ( atoms )
atoms = ( 3.89 x 10²¹) x 7 / 1
atoms = <span>2.72 x 10²² atoms of P2O5
Hope this helps!!!
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