Two unknown liquids, A and B, were reacted to form a solid C and liquid D. The products of the reaction resemble those of an acid-base reaction. With these observations, can we determine whether liquid A, liquid B, solid C, and liquid D are elements or compounds?

Classify each substance as an element, a compound, a homogeneous mixture or a heterogeneous mixture.

Classify each substance as an element, a compound, a homogeneous mixture or a heterogeneous mixture.
i. nitrous oxide
ii. rainwater
iii. silver
iv. salad

Identify the hypothesis among the following statements.

Identify which of the following is NOT an observation.

a. Heat is released when an acid is neutralized with a base.

b. Energy is converted from one form to another.

c. Iodine vapor is color purple.

d. The distance between A and B is 5 m.

Classify the following separation method as distillation, filtration, or chromatography: Removing dust and other particulates from the air using air purifiers.