A student measures her computer keyboard with a meter stick and finds that it has a width of 47.35 cm. Which statement about this measurement is true? PL HELP

A.) All the numbers are certain
B.) The 4 is uncertain
C.) The 5 is somewhat uncertain
D.) The 5 is certain ​

Consider the reaction of a(g) + b(g) + c(g) => d(g) for which the following data were obtained: experiment initial [a], mol/l initial [b], mol/l initial [c], mol/l initial rate, mol/l.s 1 0.0500 0.0500 0.0100 6.25 x 10^-3 2 0.100 0.0500 0.0100 2.50 x 10^-2 3 0.100 0.100 0.0100 1.00 x 10^-1 4 0.0500 0.0500 0.0200 6.25 x 10^-3 what is the rate law for the reaction?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments