What makes the element named iron (Fe) different from the element named nickel (Ni)?
A.
The only difference is the name of the element.
B.
Iron is a solid but nickel is a gas.
C.
Atoms of iron are different from atoms of nickel.
D.
Iron is made of atoms but nickel is not.

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

What substance has a mass of 9.5g and volume of 2.1cm^3

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?