2The higher the numbers on the NFPA diamond, the more the substance is. ARare incorrect answer
BDangerous incorrect answer
CPure incorrect answer
DSafe

The correct answer is B. Dangerous

Explanation:

The NFPA diamond is used to show how safe or dangerous a substance or material is based on four main categories: Health (blue), Flammability (red), Instability (yellow), special hazards (white). Moreover, the three first hazards are expressed using numbers from 0 to 4, in which 0 means no hazard while 4 is the most dangerous category. For example, in the health square finding 0 means the substance represents no hazard for health, while 4 means the substance is lethal. This means the higher the number in this diamond, the most dangerous the substance is.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements