Which chemical equation is unbalanced?

1. C + O2 → CO2

2. Sr + O2 → 2SrO

3.6H2 + 3O2 → 6H2O

4. H2 + H2 + O2 → H2O + H2O

The density of copper is 8.9 g/cm3. If you have 90.0 grams of copper, how much volume is your copper occupying

Use the term that means "a change in velocity" in a complete sentence

What is the symbol for magnesium

A jar contains helium gas. what would happen if the lid of this Jar was removed

Examine the following isotopes of silicon (Si). silicon-28 (28Si) silicon-29 (29Si) silicon-30 (30Si) What is true about these isotopes? They all have the same number of protons and neutrons.

100 ml oxygen at 1.75 atm and 200ml nitrogen at 0.6 atm are passed to a 500 ml vessel. Calculate the total pressure of the mixture in the vessel at same temperature

Which is the best metal to use in an alloy to increase its electrical conductivity

Ice does not need to melt into liquid water before it can return to the atmosphere as water vapor. a. True b. False

How much ice at a temperature of - 17.5 ∘C must be dropped into the water so that the final temperature of the system will be 31.0 ∘C?

Why does a gas fill completely the vessel in which it is kept?