Helium has two protons, two neutrons and two electrons. what is the charge of this atom?

a. 0

b. 2

c. 4

d. more information is needed.

A student measures the mass of a beaker filled with corn oil. The mass reading averages 200.6 g and the mass of the beaker is 10.69 g. What is the mass of the corn oil? Answer in units of g.

Why is the air pressure greater on the mountain top

If 4.0 moles of X and 4.0 moles of Y react according to the hypothetical reaction below, how many moles of the excess reactant will be left over at the end of the reaction? 2X + 3Y yields X2Y3 1.3 mol Y left over 2.7 mol Y left over 1.

How many coulombs pass through an electrolytic cell when a current of 1.37 A is applied for 3.0 min?

Mechanical weathering occurs at a greater rate in climates that are

If a sample containing 2.50 ml of nitroglycerin (density=1.592g/ml) is detonated, how many total moles of gas are produced?

A helium balloon initially at room temperature is dunked into a bucket of liquid nitrogen (T = 77 K). Which of the following will occur?

Which statements indicate what the fossil record suggests about evolution on Earth? Check all that apply. Humans have only recently existed on Earth. Organisms originally lived only in Earth's water. Life on Earth started when water formed on Earth.

What does homogeneous mixture of elements mean

As an acid is added to neutral water the [OH-] will