Answer:
1B +4St+1Y+3lc——-> BSt4Ylc3
Explanation:
I only know the answer for the first question.
The best answer is the isotope of strontium which is strontium-85. It has a half-life of about 64 days. The metal strontioum has four stable, naturally occurring isotopes which includes 84Sr (0.56%), 86Sr (9.86%), 87Sr (7.0%) and 88Sr (82.58%).
Se: Selenium
Protons: 34
Electrons: All atoms in the periodic table are neutral until changed otherwise
Neutrons: 44
Atomic Mass: 78.09
>Symbol attached<
Answer: Option (A) is the correct answer.
Explanation:
Atomic number of sodium is 11 and its electronic configuration is
.
In order to gain stability, sodium loses one electron and hence it forms a positive ion
.
Thus, we can conclude that when sodium combines with chlorine, it has a net charge of +1 because sodium loses a negative electron when forming chemical bonds.