Which of these substances are molecules?

1. H2O

2. NaCI

3. N2

4. O2

Answer choices

A) 1&2

B) All of them

C) None of them

D) 3&4

Which of these instruments sends its measurements directly to a computer? A. graduated cylinder B. stopwatch C. temperature probe D. pH paper

Which element mo se na or br contains the most moles of atoms in a 1.0 gram sample?

18 Powdered sulfur is yellow, and powdered iron is gray. When powdered sulfur and powdered iron are mixed at 20°C, the powdered iron (1) becomes yellow (3) remains ionic (2) becomes a liquid (4) remains magnetic

Briefly explain the process of refining of petroleum.

Which one of these is not an example of intracellular communication? A. A finger is suddenly removed from a hot object. B. A bone cell maintains homeostasis. C. Molecular movement occurs within a cell. D.

Which formula id correctly paired with its name? A. MgSO↓ = magnesium chlorine B. FeO = iron (|||) oxide C. K↓2O = Phosphorus dioxide D. CuCI↓2 = copper (||) chloride

Which of the following correctly explains the role of enzymes in biochemical reactions? A) Enzymes provide energy in the form of ATP to lower the activation energy needed for the reaction.

How does being a landlord relate to chemistry in any way

Element m has an ellectronegativity of less than 1.2 and reacts with bromine to form the compound MBr2. Element M could be?

Which situation describes evidence of a chemical change? A. When food color is added to water, it changes color. B. A solid changes into liquid when heated. C. A solution feels warm after a cool solid is added to it. D.