Which of the following is NOT an example of a physical change?

a. the shaping of a gold bar

b. the explosion of fireworks

c. the melting of a Popsicle

d. the sanding of a piece of wood

Some ionic compounds do not dissolve in water because ... a) the ionic bonds are too strong to be broken by the attraction of the water molecules b) they float on the surface c) water is a covalent compound so it cant dissolve ionic compouds d)

A solution of H 2 SO 4 (aq) with a molal concentration of 1.94 m has a density of 1.119 g / mL. What is the molar concentration of this solution?

What are four types of research in chemistry

what is the volume in liters of 76 grams of fluorine (f2) at a temperature of 0 celcius and 101.3 kilopascals?

What happens when an electron moves from a high energy level to a lower one? A. it absorbs light B. it emits light C. it disappears D. it gets bigger

Which orbital notation represents a noble gas in the ground state

c. When we heat water up by the Bunsen burner, what temperature is the boiling water? After 10 minutes

Assuming that air contains 78 percent N2, 21 percent O2 and 1 percent Ar, all by volume. How many molecules of each type of gas are present in 1.0 L of air at STP?

Two children are playing tag. Child A who is doing the chasing can run 100m in 24 seconds Child B is running away from child A and can run 64m in 21 seconds.

What ion does a base increase