1 point You have 50 atoms of an unknown radioisotope that has a half-life of 10.0 minutes.
How many half-lives have passed if it has been 200 minutes?
(Provide the value in the space provided)
After 20.0 minutes,
type your answer...
half-lives have passed.

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.

Element j is 1s 2s 2p 3s . (i) how many unpaired electrons does j have? (ii) is j a good oxidizing agent or a reducing agent? (iii) state reason for the answer.

Arrange the elements in order of increasing electronegativity. use the periodic table to you arrange the elements. p o k mg