Express the value of exactly 15 centimeters to three significant figures.

How many carbon atoms are there in a 2.4-carat diamond? diamonds are a form of pure carbon. (1 carat=0.20 grams) ?

Examine the false statement. Weak acids always have a high pH. Select the rewording that makes the statement true. Strong acids always have a high pH. Weak acids always partially dissociate. Strong acids always have a low pH.

How many liters of 4.0 M NaOH solution will react with 1.8 mol H2SO4? (Remember to balance the equation.

Something breaking is an example of what kind of change? A. physical only B. chemical only C. physical and chemical

15. Which state of matter has a definite volume and takes the shape of its container? liquid gas solid

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

What is the definition of Amplitude?

An excess of NiCO3, 12 g, was added to 40cm cube of sulpheric acid, 2.0 mol/dm cube. The unreacted nickel carbonate was filtered out and the filtrate evaporated to optain the crystals.