A particular radioactive isotope has a half-life of (2.50+a) hours. if you have (24.5+b) g of the isotope at 10:00 am, how much will you have at 7:30pm? give your answer in grams (g) and with 3 significant figures.

Give the number of protons, electrons, and neutrons in the following atoms a. 90Zr b. 202Hg c. 58Ni d. 222Rn

Which of the following could be classified as matter? Check all of the boxes that apply. desk water idea cloud helium dream

What is a synonym for the word preserved? A. Wasted B. Conserved C. Endangered D. Released

If cacl2 is dissolved in water, what can be said about the concentration of the ca2 + ion? hints if is dissolved in water, what can be said about the concentration of the ion? it has the same concentration as the cl - ion.

Which term refers to a substance that is formed in one step of a reaction mechanism and consumed in a subsequent step of the reaction mechanism?

Which sub-layer thins out into space, where there is no air

Complete and balance the molecular equation, including phases, for the reaction of aqueous ammonium bromide, nh4br, and aqueous lead (ii) acetate, pb (c2h3o2) 2.

A magnesium atom has 2 valence electrons in its third shell. Which is a TRUE statement about what happens when it forms an ion? A. It will be an anion. B. It will have more electrons than protons. C.

What scientific discoveries led to changes in Dalton's atomic theory?

What does berkelium react with