Wind ,ice,and water eroded it over years
Answer is: <span>a hill over which a wagon is pushed.
</span>For all chemical
reaction some energy is required and that energy is called activation
energy (<span>energy
that needs to be absorbed for a chemical reaction to start)<span>.
There are two types of reaction: endothermic
reaction (chemical reaction that absorbs more energy than it releases)
and exothermic reaction (chemical reaction that releases more energy than
it absorbs).
</span></span>R<span>eactions
occur faster with a catalyst because they require less activation energy.</span>
Answer: The space occupied by the gas at 400 torr and
is 250 mL.
Explanation:
Given:
= 250 mL,
= 800 torr, 
,
= 400 torr, 
Formula used is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that space occupied by the gas at 400 torr and
is 250 mL.
You should put a picture or finish the question
Answer:
pH = 6.8124
Explanation:
We know pH decreases with increase in temperature.
At room temperature i.e. 25⁰c pH of pure water is equal to 7
We know
Kw = [H⁺][OH⁻]...............(1)
where Kw = water dissociation constant
At equilibrium [H⁺] = [OH⁻]
So at 37⁰c i.e body temperature Kw = 2.4 × 10⁻¹⁴
From equation (1)
[H⁺]² = 2.4 × 10⁻¹⁴
[H⁺] = √2.4 × 10⁻¹⁴
[H⁺] = 1.54 × 10⁻⁷
pH = - log[H⁺]
= - log{1.54 × 10⁻⁷}
= 6.812