A) Energy is released during the formation of the bond.
Explanation:
During the formation of a chemical bonds between two hydrogen atoms, energy is always released during the formation of this bond type.
Bond formation process is usually exothermic and energy is released during the formation of the bond.
- Bond breaking process is an endothermic process in which energy is absorbed from the surrounding.
- Whenever a bond is broken, the bond energy value is positive but when a bond is formed, the bond energy value is given a negative sign.
For a bond formation process in which hydrogen atoms are bonded covalently, energy is usually released.
Learn more:
Enthalpy changes brainly.com/question/10567109
#learnwithBrainly
The answer is D, reactant.
Answer:
Explanation:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
On left side of periodic table atoms of metals are more reactive by loosing the electrons or we can say metals are more reactive by loosing the electrons so their reactivity increase down the group because of easily removal of electrons.
On right side of periodic table atoms of nonmetals are more reactive by gaining the electrons. As we move down the group nuclear attraction becomes smaller because of shielding thus electron are less attracted by nucleus and reactivity decreases.
Answer:
3 years
Explanation:
Given data:
Initial amount of sample = 160 Kg
Amount left after 12 years = 10 Kg
Half life = ?
Solution:
at time zero = 160 Kg
1st half life = 160/2 = 80 kg
2nd half life = 80/2 = 40 kg
3rd half life = 40 / 2 = 20 kg
4th half life = 20 / 2 = 10 kg
Half life:
HL = elapsed time / half life
12 years / 4 = 3 years
