28.01 g/mol
hope that helped
Answer:
D
Explanation:
I think it is D. Think about it- if a human jumps, they are less than the gravitational force. But, if you are greater than the gravitational force, I think you will go into space.
The molecular formula for compound is
mass of compound is 0.670 g.
To calculate number of atoms first calculate number of moles in the compound as follows:

Molar mass of
is 283.886 g/mol, thus,

Thus, number of mole of
is 0.00236 mol.
From the molecular formula 1 mole of
has 2 mol of P (phosphorus) and 5 mol of O (oxygen).
Thus, number of moles of P and O in 0.00236 mol of
will be:

Similarly,

Now, in 1 mol of an element there are
atoms.
Number of atoms of P will be:

Similarly, number of atoms of O will be:

Total number of atoms will be sum of number of atoms of P and O:

Therefore, total number of atoms in
will be
.
Answer:
B) They will react because X and Y can share two pairs of electrons to become stable
Explanation:
The electron configurations of two elements x and y are given :
X: 1s2 2s2 2p6
Y: 1s2 2s2 2p6 3s2 3p6
The statement that is true for both the elements is that, they both will react as they both can share two pairs of electrons to become stable.
To become stable the outermost shell or p orbital should have 8 electrons, so element X can gain 2 atoms to become stable.
Element Y can also react as it can also share two atoms to fulfill its 3p orbital and will stable.
Hence, the correct option is "B".