Question

a) What is true about how atoms are bound together in a solid?

b) What is mass density?

c) What is weight density?

d) What is volume?

e) What is surface area?

Answer 1

A) A standard ionic solid consists of atoms held together by ionic bonds, that is by the electrostatic attraction of opposite charges (the result of transferring electrons from atoms with lower electronegativity to atoms with higher electronegativity. Atoms are arranged like closely packed spheres. Because outer electrons of metal atoms are delocalized and highly mobile, metals have electrical and thermal conductivity.

B) Mass density represents the mass (or number of particles) per unit volume of a substance, material or object. Mass density is a quantitative expression of the amount of mass contained per unit volume. The standard unit is kilograms per meter cubed (kg/m3). The symbol most often used for density is (the Greek letter rho). Mass density is also known as density.

C) Weight Density or Specific Weight is defined as the weight per unit volume at standard temperature and pressure. It is usually denoted by w.

w= ρg

D) Volume is the quantity of three-dimensional space enclosed by a closed surface, for example, the space that a substance (solid, liquid, gas, or plasma) or shape occupies or contains. Volume is often quantified numerically using the SI derived unit, the cubic metre.

E) The definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc length of one-dimensional curves, or of the surface area for polyhedra (i.e., objects with flat polygonal faces), for which the surface area is the sum of the areas of its faces.