Which of these is an indication that a chemical reaction has occurred?

A.) formation of gas

B.) Boiling of a substance

C.) Melting of a substance

D.) freezing of a substance

If a buffer solution is 0.540 M in a weak acid (K a = 8.0 * 10 - 6) and 0.230 M in its conjugate base, what is the pH?

A student isolated 25 g of a compound following a procedure that would theoretically yield 81 g. What was his percent yield?

Which of the following pairs of elements could possibly be found in the same group on the periodic table? A is an alkali metal; B forms a 1 - ion. A has two valence electrons; B forms a 2 - ion. A is a noble gas; B has seven valence electrons.

How do i balance this Na + Cl² = NaCl

What is the strongest metal known to man? may mark brainliest

Identify the precipitate (if any) that forms when KOH and Cu (NO3) 2 are mixed

An atom has a mass number of 27 and 14 neutrons. what is the atomic number of this atom?

The two forms of oxygen, O2 (g) and O3 (g), have (1) different molecular structures and identical properties (2) different molecular structures and different properties (3) identical molecular structures and identical properties (4) identical

What is the difference between a distraction and a reaction

if carbon which has an electrongavity of 2.5 bonds with hydrogen, which has an electrongavity of 2.1, the bond between the two atoms will be classified as a (n) covalent bond