Hydrocarbons are composed of the elements

(1) carbon and hydrogen, only

(2) carbon and oxygen, only

(3) carbon, hydrogen and oxygen

(4) carbon, nitrogen and oxygen

The number of atoms in a mole of any pure substance is called

Which element is magnetic? calcium chromium carbon cobalt

Which of the following answer choices best describes J. J. Thomson's plum-pudding model? An atom is surrounded by a firm outer shell and contains positively charged particles in its core.

If an equal number of moles of the weak acid hf and the strong base naoh are added to water, is the resulting solution acidic, basic, or neutral?

B. C6H1206 (s) → CH4 (9) + CO2 (g) what is this in words

A population of crabs live on a light-colored sandy beach. In this environment there is a population of birds that eat the crabs. One year, there is a volcanic eruption near the beach and dark volcanic ash covers the beach.

It would take one light year to travel to the sun? True or false?

A specific, electrically neutral atom of boron has 5 protons, 5 electrons, and 6 neutrons. what is the mass number of this atom of boron? 6 5 11 16

When does hail happen?

For the reaction, calculate how many moles of the product form when 0.012 mol of O2 completely reacts. Assume that there is more than enough of the other reactant. 4Al (s) + 3O2 (g) →2Al2O3 (s) Express your answer using two significant figures.