Half life is 100 years.
after 1st life the number of isotopes remaining =100/2=50
after 2nd half life the number of isotopes remaining=50/2=25
Answer:
oxidation number is correct!! :)
Explanation:
Answer:
See explanation
Explanation:
Since iron is a metal and oxygen is a non metal, a bond is formed between the two when electrons are transferred from iron to oxygen. Hence the bond is ionic.
Two silver atoms are held together by metallic bonds. Metallic bond are bond forces that exist between metal atoms in a crystal lattice. The valence electrons in this bond form a cloud. Metals have low ionization energy and low electronegativity hence they loose electrons easily. This accounts for the nature of the metallic bond.
The bond formed between two chlorine atoms is a covalent bond. The valence electrons in this bond are localized between the two chlorine atoms. Chlorine is a nonmetal hence it has a high ionization energy and high electronegativity. Hence it forms covalent bonds in which electrons are shared between bonding atoms.
Urmmm??????? What is the question
Answer:
A and C are true , B and D are false
Explanation:
For A)
from the first law of thermodynamics (in differential form)
dU= δQ - δW = δQ - PdV
from the second law
dS ≥ δQ/T
then
dU ≤ T*dS - p*dV
dU - T*dS + p*dV ≤ 0
from the definition of Gibbs free energy
G=H - TS = U+ PV - TS → dG= dU + p*dV + V*dp - T*dS - S*dT
dG - V*dp + S*dT = dU - T*dS + p*dV ≤ 0
dG ≤ V*dp - S*dT
in equilibrium, pressure and temperature remains constant ( dp=0 and dT=0). Thus
dG ≤ 0
ΔG ≤ 0
therefore the gibbs free energy should decrease in an spontaneous process → A reaction with a negative Gibbs standard free energy is thermodynamically spontaneous under standard conditions
For B) Since the standard reduction potential is related with the Gibbs standard free energy through:
ΔG⁰=-n*F*E⁰
then, when ΔG⁰ is negative , E⁰ is positive and therefore a coupled redox reaction with a positive standard reduction potential is thermodynamically spontaneous.
