True
This statement is read as "A is a subset of B" which means that all elements contained in set A are a part of set B.
From the chemical formula the total mass of the compound can be determined. The mass of the 1 mole of the compound is its molar mass. The atom by which the molecule is generated, the mass of these atoms are expressed in terms of amu or atomic unit mass, but after formation of a molecule in a particular ratio the mass of each of the atom becomes the total molecular weight of the generated molecule. In this case the molecule posses three atoms X, Y and Z which are in a ratio of 2:2:7. Thus the chemical formula of the compound can be written as
.
So the total mass of the compound in amu is {(2×47)+(2×42)+(7×16)} = {94+84+112}=290 amu.
Thus 1 mole of the compound contains 290 amu or 290 g by mass.
Henceforth 20 gram of the compound is equivalent to (20/290) = 0.068 mole.
Answer:
c. An ionic bond is much stronger than most covalent bonds
Explanation:
Ionic bonds are interatomic bonds that forms as a result of electrostatic attraction between two ions. For an ionic bond to be formed, one atom must have lost or gained electron from another that is transferring it. Ionic bonds typically form between atoms whose electronegativity differences are far apart.
Ionic bonds are usually stronger than other types of bonds due to the electrostatic attraction between ions.
One very distinct feature about ionic compounds is that they are conductors of electricity in either molten or aqueous. At room temperature, they are solids and contains no mobile ions.