Answer:
hi!
Explanation:
Well, some things I would do is to know the Periodic Table font and back. Know they elements and their class and atomic number and weight. Know how many atoms make up each element and how many protons, neutrons, and elements are in each atom.
The Selenium is the element that is likely to be the most brittle
Group 7A are halogens
If you look at a periodic table, these elements include F, Cl, Br, I, and At. Some well known salts are KCl and NaCl (better known as table salt!)
Answer:
The equation is Fe₂O₃ + CO ⇒ Fe + CO₂.
The balanced reaction equation is Fe₂O₃ + 3CO ⇒ 2Fe + 3CO₂.
Explanation:
First, we have to write our equation. It's actually pretty straightforward - first we look for our reactants (looks like it's Fe₂O₃ and CO), then we look for our products (Fe and CO₂). Then, we have to balance it so that both sides have the same number of both element.
Currently, we have the equation Fe₂O₃ + CO ⇒ Fe + CO₂. There are 2 Fe atoms, 4 O atoms, and 1 C atom on the left side. There is 1 Fe atom, 2 O atoms, and 1 C atom on the right side.
First thing we can do is give our Fe on the right side a coefficient of 2. This will make it equivalent to the 2 Fe atoms on the left side:
Fe₂O₃ + CO ⇒ 2Fe + CO₂
Next, we need to make sure that we have the same number of C and O atoms on each side. This takes a little bit of thinking, but what we have to do is give CO a coefficient of 3 and CO₂ a coefficient of 3. This gives us 6 O atoms on the left side (when we include the O₃) and 6 O atoms on the right side (since there are 3 O₂ atoms and 3 times 2 is 6). Here's what that looks like:
Fe₂O₃ + 3CO ⇒ 2Fe + 3CO₂
And that's how I balanced the equation. It can be confusing, but with enough practice, it will get easier and easier. :)
Answer: Th enthalpy of combustion for the given reaction is 594.244 kJ/mol
Explanation: Enthalpy of combustion is defined as the decomposition of a substance in the presence of oxygen gas.
W are given a chemical reaction:



To calculate the enthalpy change, we use the formula:

This is the amount of energy released when 0.1326 grams of sample was burned.
So, energy released when 1 gram of sample was burned is = 
Energy 1 mole of magnesium is being combusted, so to calculate the energy released when 1 mole of magnesium ( that is 24 g/mol of magnesium) is being combusted will be:
