The mass number of an element is equal to

a. the total number of electrons.

b. the sum of the protons and neutrons.

c. less than twice the atomic number.

d. a constant number for the lighter elements.

Which prediction about a methane molecule would most likely be made by using both the quantum model of the atom and John Dalton's model? A. when the molecule reacts new atoms are created B. the molecule contains different kinds atoms C.

Two samples of carbon tetrachloride were decomposed into their constituent elements. One sample produced 38.9 g of carbon and 463 g of chlorine, and the other sample produced 14.8 g of carbon and 144 g of chlorine.

On earth, an object that contain more matter than another will always have

How many moles of carbon dioxide should be produced from the decomposition of 0.100 g of sodium bicarbonate?

Calculate the mass of precipitate that forms when 250.0 mL of an aqueous solution containing 35.5 g of lead (II) nitrate reacts with excess sodium iodide solution.

Which structures are found on sponges? pores medusae polyps stinging cells

Coefficients in a chemical equation are used to: balance the number of atoms on both sides of the equation ensure that all subscripts on both sides of the equation are the same indicate energy changes that occur during the reaction indicate the type

What determines your blood cholesterol level?

Describe two ways that water moves through earthy atmosphere in the water cycle.

which of the following questions can use science as a method of inquiry? a. is cloning appropriate b. how can we protect crops from drought c. why is jazz a great type of music d. did dinosaurs exist