Why is helium in group 18 on the periodic table though it only has 2 valence electrons?

In the explosion of a hydrogen-filled balloon, 0.40 g of hydrogen reacted with 3.2 g of oxygen. How many grams of water vapor are formed? (water vapor is the only product.) express your answer using two significant figures.

9. I've been called a "storage tank" by those with little taste. I'm a sac filled with water, food, enzymes, or waste.

True or false the three types of seismic waves are P eaves, S waves, and T waves

The molecules of Any Given substance are always

The earth is only several thousands of years old. True False

What is the empirical formula of a compound composed of 32.9g of potassium and 6.73 g of oxygen

Glucose is not made from which of the following

Rank the temperatures from the highest to the lowest. 133F 351K 25C 273K 146C 58F 95F

Calculate the density of sulfuric acid if 35.4 mL of the acid weighs 65.14 g.

Where the single machos?