Answer:
High activation energy is the reason behind unsuccessful reaction.
Explanation:
There are two types of reaction: (1) thermodynamically controlled reaction and (2) kinetically controlled reaction.
Thermodynamically controlled reaction are associated with change in enthalpy during reaction. More negative the enthalpy change, more favored will be the reaction.
Kinetically controlled reaction are associated with activation energy of a reaction. The lower the activation energy value, the more rapid will be the reaction.
Here, reaction between 
and 
is thermodynamically favored due to negative enthalpy change but the high activation energy does not allow the reaction to take place by simple mixing.
Answer:
- contains oxygen
- provides warmth
- blocks harmful energy from the Sun
Explanation:
The atmosphere is crucial when it comes to providing living conditions on Earth. The gases in the atmosphere manage to balance the things just about right, so that the life can thrive. The atmosphere has oxygen, the gas that is used by pretty much every organism to be able to function. With its greenhouse gases, the atmosphere manages to trap the heat inside, thus providing warmth to the Earth. The numerous layers of the atmosphere manage to block in big portion the harmful energy from the Sun, with a special accent on the ozone layer, a layer that manages to stop most of the UV radiation.
Answer:
TRIAL 1:
For “Event 0”, put 100 pennies in a large plastic or cardboard container.
For “Event 1”, shake the container 10 times. This represents a radioactive decay event.
Open the lid. Remove all the pennies that have turned up tails. Record the number removed.
Record the number of radioactive pennies remaining.
For “Event 2”, replace the lid and repeat steps 2 to 4.
Repeat for Events 3, 4, 5 … until no pennies remain in the container.
TRIAL 2:
Repeat Trial 1, starting anew with 100 pennies.
Calculate for each event the average number of radioactive pennies that remain after shaking.
Plot the average number of radioactive pennies after shaking vs. the Event Number. Start with Event 0, when all the pennies are radioactive. Estimate the half-life — the number of events required for half of the pennies to decay.
Explanation:
I think the second choice but I might be wrong
