Answer:
8 valence electrons
Explanation:
There are 4 valence electrons in carbon because it is in group 4A of the periodic table. There is 1 valence electron per hydrogen based on its position on the periodic table, but CH4 has 4 hydrogens in it. So 1 times 4 is 4. Add the 4 valence electrons from carbon with the 4 electrons from H4 to get 8.
Answer:
It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.
Explanation:
A → B
Initial concentration of the reactant = x
Final concentration of reactant = 10% of x = 0.1 x
Time taken by the sample, t = ?
Formula used :

where,
= initial concentration of reactant
A = concentration of reactant left after the time, (t)
= half life of the first order conversion = 56.6 hour
= rate constant

Now put all the given values in this formula, we get

t = 188.06 hour
It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.
Explanation:
It happens because particles of gas are in constant random motion. Thus they can collide with the walls of the container causing pressure on the walls.
Chemical reactions are a change in substance while nuclear is destruction
Answer: Chosen landforms are:
1) Hill
2) Mountain
3) Plateau
4) Valley
Explanation:
1) Hill is an elevated location smaller than a mountain. Location: Land
2) Mountain is a large mass of earth and rock, rising above the common level of the earth or adjacent land, usually given by geographers as above 1000 feet in height (or 304.8 metres).
Location: Land or Water
3) Plateau is a largely level expanse of land at a high elevation. It is also known as tableland.
Location: Land
4) Valley is an elongated depression between hills or mountains, often with a river flowing through it.
Location: Land or Water