It's b. calcium
because the outer electron structure in all of that element is similar, they have the same chemical and physical properties.<span />
A proton has a positive charge of 1
Answer:
I think its the first one
Explanation:
Answer:
E = 8.84×10⁻¹⁷ J
Explanation:
Given data:
Wavelength of wave = 2.25 nm (2.25×10⁻⁹ m)
Energy of wave = ?
Solution:
Formula:
E = hc/λ
c = 3×10⁸m/s
h =6.63 ×10⁻³⁴ Js
now we will put the values,
E = 6.63 ×10⁻³⁴ Js × 3×10⁸m/s / 2.25×10⁻⁹ m
E = 19.89×10⁻²⁶ Jm / 2.25×10⁻⁹ m
E = 8.84×10⁻¹⁷ J
In a chemical reaction mass is neither created nor destroyed
