I think the correct answer from the list of choices above is option B. <span>The chemical combination of two or more different atoms in fixed amounts is called a compound. There are two type of compounds namely the ionic and covalent compounds.</span>
The best and most correct answer among the choices provided by your question is the first choice or letter A.
A ph of 7 contains only water.
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2.258625 *10²³ oxygen atoms will be produced.
<h3><u>Explanation:</u></h3>
Decomposition reaction is defined as the type of reaction where one single reactant breaks to produce more than one product only by means of heat or other external factor.
Formula of magnesium oxide = MgO.
The molecular mass of magnesium oxide = 24 +16= 40.
So in 40 grams of magnesium oxide, number of molecules is 6.023 * 10²³.
So in 15 grams of magnesium oxide,, number of molecules is 6.023 *1023 * 15/40 = 2.258625 *10²³.
From one molecule of magnesium oxide, one oxide atom will be produced.
So number of oxide atoms with 100% yeild = 2.258625 *10²³
Answer: P₂=0.44 atm
Explanation:
For this problem, we are dealing with temperature and pressure. We will need to use Gay-Lussac's Law.
Gay-Lussac's Law: 
First, let's do some conversions. Anytime we deal with the Ideal Gas Law and the different laws, we need to make sure our temperature is in Kelvins. Since T₂ is 64°C, we must change it to K.
64+273K=337K
Now, it may be uncomfortable to use kPa instead of atm, so let's convert kPa to atm.
Since our units are in atm and K, we can use Gay-Lussac's Law to find P₂.
P₂=0.44 atm
Answer: 77.7g
Explanation:Please see attachment for explanation
