How many valence electrons are there in each of the following elements AND COMPOUNDS (add up the valence electrons for each atom). Show your addition for the compounds:
18) Ca
19) P
20) Se
21) NH3
22) NF3
23) Al2(CO3)3

In which phase(s) do the molecules take the shape of the container?

Ill give brainiestif one neutron initiates a fission event that produces two neutrons in the products, how many new reactions can now be initiated? if each of the neutrons produced in the first fission event then initiates a fission event that produces one neutron in the products, how many new reactions can now be initiated by each neutron? how many neutrons in total were produced by the two fission events described?

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm