1.Type of bonding in which electrons are completely transferred is called ionic bond.
2. Isotopes have same atomic number but different atomic mass number.
Atomic number = number of protons + number of neutrons
Therefore, A is correct.
3. Nucleus is composed of neutrons and protons.
4. Chemical reactions follows the law of conservation of mass. Therefore mass of reactant = mass of product = 4 grams.
5. Again, mass of table salt formed should be equal to mass of (Na+Cl₂) = 4 grams.
Radioactive material obeys 1st order decay kinetics,
For 1st order reaction, we have
k =
where, k = rate constant of reaction
Given: Initial conc. 100, Final conc. = 6.25, t = 18.9 hours
∴ k =
= 0.1467 hours^(-1)
Now, for 1st order reactions: half life =
= 4.723 hours.
Answer:
Carbon, germanium, tin and lead.
Explanation:
The silicon is belong to the carbon family. There are five elements in carbon family carbon, silicon, germanium, tin and lead. These five elements are present in same group i.e group fourteen. The elements present in same group have same number of valance electrons.
For example.
Carbon electronic configuration:
C₆ = [He] 2s² 2p²
Silicon electronic configuration:
Si₁₄ = [Ne] 3s² 3p²
Germanium electronic configuration:
Ge₃₂ = [Ar] 3d¹⁰ 4s² 4p²
Tin electronic configuration:
Sn₅₀ = [Kr] 4d¹⁰ 5s² 5p²
Lead electronic configuration:
Pb₈₂ = [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²
we can see that in case of all elements there are four valance electrons, which are equal to the valance electrons of silicon.
