3s it is what it says sorry if this is wrong but I just did a qu like this and that's what it was
Answer:
yes its really easy but what to do in this ??
The two dimensions of aluminum foil are given 13.72 cm and 8.63 cm respectively with mass 3.1 g.
The density of aluminum is
. It is defined as mass per unit volume thus, volume of aluminum can be calculated as follows:

Putting the values.

The volume of cuboid is
, the length and breadth are given, height can be calculated as follows;

Putting the values,

Or, approximately 9.7\times 10^{-3}cm
Therefore, thickness of aluminum foil is 
Answer: Option C is correct
A polar molecule with nonpolar bonds
Explanation:
A polar molecule with nonpolar bonds cannot be polar because a polar molecule has net dipole that it has one end slightly positive and the other end slightly negative which allows the distribution of atoms .
Therefore it cannot have non polar bonds because non polar bonds allow electrons to be shared equally and it take place between non elemental substances or substances that are not elements , it cannot occur in elemental substances because these substances have different electronegativities which can be held by polar bonds alone.
Answer:
The mass number (A) of an atom is the total number of protons and neutrons in its nucleus. ... Because electrons have virtually no mass, just about all the mass of an atom is in its protons and neutrons. Therefore, the total number of protons and neutrons in an atom determines its mass in atomic mass units (Table 4.5. 1).