Express 0.000000384 in scientific notation

What is the main element that stars are made of

Write two balanced equations 1. Dissolving of Solid Sodium Hydroxide in Water 2. The reaction of Sodium Hydroxide Solution with Hydrochloric Acid

Aluminum is an element. Which best describes what makes up a sample of aluminum? A. one kind of atom B. two different kinds of atoms C. all carbon-based atoms D. a carbon atom and non-carbon atoms

A rock weighing 32.0 g is placed in in a graduated cylinder displacing the volume from 22.3 mL to 27.6 mL. What is the density of the rock in grams/cubic centimeter?

A compound that contains both potassium and oxygen formed when potassium metal was burned in oxygen gas. the mass of the compound was 7.11 grams. The mass of the potassium metal was 3.91 grams.

What do igneous rocks form from? (20pts!)

A gas at STP has a volume of 1.0 liter. If the pressure is doubled and the temperature remains constant, the new volume of the gas will be ... ?

Combustion analysis of toluene, a common organic solvent, gives 8.20 mg of co2 and 1.92 mg of h2o. if the compound contains only carbon and hydrogen, what is its empirical formula?

Why does the moon have phases? What are the four main phases of the moon? How long does it take to change from one to another?

How many atoms are in 1/2 mole of calcium