Radium-226 is a common isotope on earth, but it has a half-life of about 1620 years. given that earth is some 5 billion years old, why is there any radium at all?

Solid iron has a density of 7.9 g/cm3. Liquid mercury has a density of 13.6 g/cm3. will iron float or sink in mercury?

A 1.543 gram sample containing sulfate ion was treated with barium chloride reagent, and 0.2243 grams of barium sulfate was isolated. calculate the percentage of sulfate ion in the sample.

You have a 3.5 x 10^-5 M solution of perchloric acid. a.) Can you determine the pH of this solution? Explain why or why not. b.) If yes, what is the pH of this solution? Show all work.

Margo draws a triangle. The lengths of the sides of the triangle are 8 inches, 15 inches, and 17 inches. Margo uses the area of three squares to show that the triangle is a right triangle.

As altitude increases what, is the trend in the amount of air pressure in the atmoshere?

Which one is correct A. It allowed them to escape B. It allowed them to chase down C. It allowed them to reach food D. All of these

Boron is one position to the left of carbon on the periodic table. the atomic number of carbon is 6. given its position on the periodic table, what is the atomic number of boron

Actions of the non-valence electrons, diluting the force of the attraction between nucleus and valence electrons is called

Which statements accurately describe the greenhouse effect? Check all that apply. It is caused by liquids on Earth's surface. It is caused by gases in Earth's atmosphere. It warms up Earth's surface and the lower atmosphere.

How is geothermal produced