Assume the half-life of a radioactive element is 250,000 years. if you start out with 16 grams of this element, how much will be left after 1.5 million years?

A line in the hydrogen spectrum occurs at 434 nm. what is the frequency of this radiation in sec - 1

The coloured gas is

Why the element with a valence of 8 is mostly likely form ionic bonds, covalent bonds or no chemical bonds with other atoms

What volume of 0.3682 M H2SO4 solution is required to react with 0.4198 grams of Al (CN) 3 according to the reaction, 2 Al (CN) 3 + 3 H2SO4  6 HCN + Al2 (SO4) 3?

What volume of silver metal will weigh exactly 2500.0g. The density of the silver is 10.5 g/cm3

Is when hot parts of the earth rise as cooler parts sink due to differences in density.

Distinguish between the structures of arteries, capillaries, and venies. what is the function of each.

Which phase of matter has a fixed volume but variable shape

Given 10.8 grams of substance Y, if the substance absorbs 231 kilojoules of energy and the specific heat of the substance is 6.55 J/g·°C, what is the change in temperature?

Which sphere includes rocks and minerals? A. atmosphere B. biosphere C. geosphere D. hydrosphere