Using the periodic table, complete the following. element: hydrogen symbol: h₂ molecular weight: g mass of one mole: g/mol

Apiece of copper has a temperature of 75.6 0c. when the metal is placed in 100.0 grams of water at 19.1 0c, the temperature rises by 5.5 0c. what is the mass of the metal?

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?