Answer:
D. bromine
Explanation:
Highest electronegativity in the period has element closest to the *A group
K Ca Cu Br
The answer is 18 you multiply wavelength (6) times frequency (3)
This problem is providing the mass, energy, initial temperature and specific heat of a sample of copper that is required to calculate the final temperature.
Thus, we recall the general heat equation:
Which has to be solved for the final temperature, 
as follows:
Finally, we plug in the numbers to obtain:
However, this result is not given in the choices.
Learn more:
Group 1A(1), the alkali metals, includes lithium, sodium, and potassium. Group 7A(17) the halogens, includes chlorine, bromine, and iodine. hope this helps:)
it is already balanced
REACTANTS
Barium sulfide (BaS) + platinum (Ii) fluoride
PRODUCT
Barium fluoride (BaF2) + Cooperite (PtS)
Hope this answer helps you dear! take care
