An element is composed of one type of atom with its own unique properties. TRUE OR FALSE

How are elements arranged in a periodic table

The minerals found in bones are deposited by living cells called

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?