Answer is: mass number is 234.
Beta decay is radioactive decay<span> in which a </span>beta ray<span> and a </span>neutrino<span> are emitted from an </span><span>atomic nucleus.
</span>There are two types of beta decay: beta minus<span> and </span>beta plus. <span> In beta minus </span><span>decay, neutron is converted to a proton and an </span>electron<span> and an </span>electron antineutrino and in beta plus <span>decay, a proton is converted to a neutron and </span>positron<span> and an </span>electron neutrino, so mass number does not change.
Answer:
D. 2:5
Explanation:
It has 5 valency electrons

Answer:
1.3×10²³ formula unit
Explanation:
Given data:
Mass of CaCl₂ = 23.8 g
Number of formula unit = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 23.8 g/110.98 g/mol
Number of moles = 0.21 mol
1 mole of any substance contain 6.022×10²³ formula unit
0.21 mol × 6.022×10²³ formula unit / 1mol
1.3×10²³ formula unit