What only happens during a chemical reaction?

A.

Colors change.

B.

New substances are formed.

C.

Bubbles form.

D.

A solution is made.

A patient needs to take 625 mg of ibuprofen twice daily. the pills are each 250 mg. how many pills does the patient need to take each time?

If the heat released during condensation goes only to warming the iron block, what is the final temperature (in ∘C∘C) of the iron block? (Assume a constant enthalpy of vaporization for water of 44.0 kJ/molkJ/mol.)

A nurse used a 0.02-mg/L solution of disinfection to clean a patients wound. What is the concentration of the solution expressed as a percentage?

One isotope of oxygen has 8 protons and 10 neutrons. Which is the correct reference for this isotope? A. oxygen-18 B. oxygen-2 C. oxygen-8 D. oxygen-10

Explain 1 way compounds of binary ionic and binary covalent substances are similar, as well as 2 ways in which they differ.

Why does bromine not react with sulphur?

What happens to the size of the atom of anon-metal as it becomes an anion? A. it decreases B. it increases C. it remains the same D. it is impossible to tell unless you know the specific element

How is oxygen and nitrogen alike

Does a gas discharge tube filled with boron emit the same wavelength

a certain solution has a molarity of m = 6.39 mol/l and has a volume of v = 0.550 l what is the value of n