E=hc/λ =6.626×10^-34×3 ×10^8 / 3×10^7 × 10^-9 = 6.626×10 ^-24J.
Answer:
A) 20
B) 40
C) Ca
D) 10
E) 9
F) F
Explanation:
The MASS NUMBER is the number of protons + the number of neutrons.
The ATOMIC NUMBER is the number of protons.
You can take the MASS NUMBER - ATOMIC NUMBER = NUMBER OF NEUTRONS.
Each element is unique and distinguished by the NUMBER OF PROTONS = ATOMIC NUMBER, ie...the number of protons in its nucleus. You can find the element's name and symbol on the Periodic Table.
The correct response is A. Only the Fe is unbalanced.
