72 moles of C2H302 are dissolved into a 3 molar solution. how many liters of water are there

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

The number at the end of an isotope’s name is the number.

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?