What is the building block of all living things why is it called a building block

An empty fuel tank can still contain and therefore can be even more dangerous than one full of liquid fuel.

Which three statements represent the benefits of performing experiments using computer simulations?

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?