The answer is 2 electrons.
The electron configuration of calcium is 2:8:8:2
Calcium has two electrons in its outermost shell. These are its valence electrons and are the ones used in bonding with other elements. Valence electrons of an atom are those electrons that are in its outer energy shell or that are available for bonding.
Calcium is a metal. When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms forming ions. The resulting compound is known as an ionic compound.
For example, when calcium metal reacts with chlorine gas, calcium gives up its two valence electrons and Chlorine accepts them resulting in a new substance called calcium chloride in which the two elements have ended up forming ionic bonds.
Answer:
n Al= 10/27( mol)- >n Al2O 3 =5/27(mol)
Explanation:
Answer:
E = 12.92 × 10^(-16) J
Explanation:
Formula for energy is;
E = hc/λ
Where;
h is Planck's constant = 6.63 x 10^(-34) J.s
c is speed of light = 3 × 10^(8) m/s
λ is wavelength = 0.154 nm = 0.154 × 10^(-9) m
E = (6.63 x 10^(-34) × 3 × 10^(8))/(0.154 × 10^(-9))
E = 12.92 × 10^(-16) J
Answer: 1.33x10^-22g
Explanation:Please see attachment for explanation
Answer:
C) 237.96682 amu
Explanation:
The symbol for neptunium-236 is given as;
²³⁶₉₃Np
This element has 93 protons and (236 - 93 = 143) neutrons.
Mass Number =Total mass of Protons + Total mass of neutrons
Total Mass pf protons = 93 * 1.007825 amu, = 93.727725 amu
Total mass of Neutrons = 143 * 1.008665 amu = 144.239095 amu
Mass = 144.239095 + 93.727725 = 237.96682 amu
Correct option is option C.
