Answer:
The first is the empirical formula which shows you the number of different atoms in the compound. After you convert the grams of each element into moles, you calculate the ratio of the moles, which gives you the ratio of the elements in the compound. More number-crunching gives you the molecular formula.
Answer:
Kr
Explanation:
The noble gas that is isoelectronic with Br⁻ is krypton.
This is because krypton is the closest noble gas to Br on the periodic table.
Electronic configuration of Bromine is;
2, 8, 18, 7
Br⁻ becomes; 2, 8, 18, 8
Krypton is; 2, 8, 18, 8
It’s true!!!!!!!!! Hope you do great in your test
So first we need to know what the formulas are:
Methane: 
Oxygen: 
Carbon Dioxide: 
Water: 
So then we follow the equation as specified in the question. Note that it does not need to be balanced, as the question states it wants the unbalanced equation:
→ 
This is the preliminary, unbalanced equation with the correct chemical formulas.
10 core electrons are in argon.