What do a mole of magnesium (Mg) and a mole of iron (Fe) have in common?

A.

their number of atoms

B.

their number of molecules

C.

their number of electrons

D.

their number of protons

How did the discoveries of scandium (Sc) and germanium (Ge) affect Mendeleev's work? A. They showed Mendeleev's table needed different groups. B. They showed Mendeleev's predictions were flawed. C. They showed Mendeleev's predictions were correct.

How many grams of copper metal are present in a 4.15g sample of copper (II) fluoride dihydrate

You have 75.0 mL of a 2.50 M solution of Na2CrO4 (aq). You also have 125 mL of a 1.79 M solution of AgNO3 (aq). Calculate the concentration of CrO42 - after the two solutions are mixed together.

Charles Lyell believed that: all rock was formed from heat and pressure catastrophic events formed the earth's features crustal rock precipitated from oceans covering the earth slow processes of erosion and deposition shaped the earth

What other signs provide evidence of chemical reactions and show that a chemical change has occurred?

To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds that it has a mass of 4.7 g. She then finds that, upon absorption of 52.

In most Acid-base reactions, what type of bond (ionic or covalent) is formed between the ions of the "salt"? What happens to the electrons in this sort of bond? Are they transferred, or shared?

Many trials are not needed before a hypothesis can be accepted

Consider the following reaction where Kp = 4.55*10-5 at 723 K: N2 (g) + 3H2 (g) ⇋ 2NH3 (g) a) If the three gases are mixed in a rigid container at 723 K so that the partial pressure of each gas is initially one atm, what will happen?

Rob measures the solubility of three different salts in water at 22°C. Which type of graph should he use to display his data? bar graph line graph histogram scatterplot