Which sample is a pure substance?

A. a test tube of zinc oxide

B. a container of zinc and oxygen

C. a flask of pond water

D. a jar of soil

How many 250 mg tablets of metronidazole are needed to make 150 ml of suspension containing 100 mg/ml?

How will you justify that ice, water and steam are the three states of a substance and not different substances?

If there are two beakers of water 1 containing 500ml and the other 100ml both at 20 degrees Celsius which has more thermal energy and why?

Which element (s) are not balanced in this equation? Fe2O3 + 3CO → 2 Fe0 + 3 CO2 Fe and O are both unbalanced. Only the Fe is unbalanced. Only the O is unbalanced. C and O are both unbalanced.

A 45 gram piece of metal has a volume of 18cm3. What is the density of this metal?

It would take one light year to travel to the sun? True or false?

A specific, electrically neutral atom of boron has 5 protons, 5 electrons, and 6 neutrons. what is the mass number of this atom of boron? 6 5 11 16

When does hail happen?

For the reaction, calculate how many moles of the product form when 0.012 mol of O2 completely reacts. Assume that there is more than enough of the other reactant. 4Al (s) + 3O2 (g) →2Al2O3 (s) Express your answer using two significant figures.

Nuclei with too many or too few neutrons are?