You have to make 500 mL of a 1.50 M BaCl2. You have 2.0 M barium chloride solution available. Determine how to make the needed dilution

You need 375 mL of BaCl2 solution.

Explanation:

M1V1=M2V2

Dilution formula. Substitute known values and solve for V1.

M1 = 2.0 M

M2 = 1.50 M

V2 = 500 mL

(2.0 M)(V1) = (1.50 M)(500 mL)

V1 = (1.50 M)(500 mL) / (2.0 M)

V1 = 375 mL

not clear

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.