Kinetic Molecular Theory states that gas particles are in constant motion and exhibit perfectly elastic collisions.
Answer:
C. They don't react with other elements to form compounds
Explanation:
The elements in Group 18 of the periodic table are called "inert", or noble gases.
These elements have their valence shell (the outermost shell of the atom) full of electrons, so they do not gain/give off electrons, and therefore, they do not react with other elements, so they do not form compounds.
In fact, normally the elements try to gain/give off electrons in order to fullfill their outermost shell (the valence shell). For instance, an atom that has 1 electron only in its valence shell, try to "give away" this electron in order to have its outermost shell completed. On the other hand, an atom which has 7 electrons in its valence shell tries to "gain" one electron in order to fullfill the valence shell.
Noble gases, instead, have already 8 electrons in their valence shell, so their valence shell is already completed, therefore they do not react with other elements, and therefore they are called "inert".
Methane was unusually high is the correct option. Hence, option B is correct.
<h3>What is methane?</h3>
Methane is the simplest member of the paraffin series of hydrocarbons and is among the most potent greenhouse gases. Its chemical formula is 
.
As the ice compacts over some time, tiny bubbles of the atmosphere or surroundings including greenhouse gases like carbon dioxide and methane—press inside the ice. These air pocket “fossils” give samples of what the atmosphere was kind when that layer of ice formed.
Based upon past studies and insights from current GHG levels, we assume that atmospheric levels of carbon dioxide and methane were unusually low.
Learn more about methane here:
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Answer: b. accepts 
ions from acids
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions 
when dissolved in water and an acid is defined as a substance which donates hydronium ions 
in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates ions and a base is defined as a substance which accepts ions.
Here water is donating ions, and thus act as acid and ammoia 
is accepting ions from water and thus is a base.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
Thus base is a substance which accepts ions from acids.
Answer:
Explanation:
equilibrium constant
Kc = [ C ]² / [ A ] [ B ]
= .5² / .2 x 3
= .4167
Let moles of A to be added be n
concentration of A unreacted becomes .2 + n M
increase of product C by .2 M will require use of A and B be .1 M
So unreacted A = .2 + n - .1 = n + .1
Kc = [ C ]² / [ A ] [ B ]
.4167 = .7² / ( n + .1 ) ( 3 - .1 )
n + .1 = .4
n = . 3 moles .
So .3 moles of A to be added .
