Answer:
18.1 g
Explanation:
You know that the atomic weight of phosphorus is equal to
30.794 u
, where
u
represent the unified atomic mass unit.
The unified atomic mass unit is equivalent to
1 g/mol
, but let's take the long road and prove that identity.
Now, the unified atomic mass unit is defined as
1
12
th
of the mass of a single unbound carbon-12 atom in its ground state and is equivalent to
1 u
=
1.660539
⋅
10
−
24
g
This means that the mass of one phosphorus atom will be
30.974
u
⋅
1.660539
⋅
10
−
24
g
1
u
=
5.14335
⋅
10
−
23
g
You know that one mole of any element contains exactly
6.022
⋅
10
23
atoms of that element - this is known as Avogadro's number.
Well, if you know the mass of one phosphorus atom, you can use Avogadro's nubmer to determine what the mass of one mole of phosphorus atoms
5.14335
⋅
10
−
23
g
atom
⋅
6.022
⋅
10
23
atoms
1 mole
=
30.974 g/mol
Finally, if one mole of phosphorus atoms has a mass of
30.974 g
, then
0.585
moles will have a mass of
0.585
moles
⋅
30.974 g
1
mole
=
18.1 g
From: https://socratic.org/questions/the-atomic-weight-of-phosphorus-is-30-974-u-what-is-the-mass-of-a-phosphorus-sam
Answer:
Pb(No3)2+2Nacl_PbCl2+2NaNO3
The answer is: They have no freedom to move.
However is not completely true, as even in a solid atoms still a move a bit (vibrations).
If atoms were able to slide past each other, then we would have a liquid not a solid. Liquids "flow" but never really "break apart" this is because atoms are sliding between them, think of these as a bucket of marbles rolling down a slope.
If they are free to move in all directions, then you have a gas; that's why someone uses perfume in a room, eventually everyone smells it.
Answer:
B
Explanation:
As you move from left to right, the number of protons increases. More protons means a bigger positive charge to pull in the electrons from the shells. This would then decrease the size of the atom.
Thus, the answer is B, the size decreases.
Hope this helps!
