Which of the following is the best indication that a chemical change has taken place?

a. The matter changes color.

b. A mixture separates into layers.

c. The change is reversible.

d. The shape of the substance changes.

Choose all the answers that apply. Calcium (Ca) has two electrons in its outermost shell. Calcium: is a metal is a nonmetal fills its shell by giving up two electrons fills its shell by gaining six electrons becomes a negatively charged ion becomes

What is required to contain warnings, after several studies that have shown that they are a suffocation risk?

The following neutral atoms each have 8 places for electrons in their outermost shells. Which atom will tend to lose rather than gain 1 or more valence electrons when forming an ion? a. Li with 1 valence electron b. O with 6 valence electrons c.

In which type of bond is an electron transferred from one atom to another? Select one: a. Covalent b. None of the answer choices c. Metallic d. Ionic

The digits that are reported in an answer are called

Suppose a 10.0 L reaction vessel is filled with 0.86 mol of BrOCl and 0.86 mol of BrCl. What can you say about the composition of the mixture in the vessel at equilibrium?

Formula for zinc nitrate

Definition: One of a class of elements having properties intermediate to metals and nonmetals.

The term southern oscillation most nearly refers to

There is more than one kind of balance used in the laboratory. true or false