Answer:
Combination or synthesis
Explanation:
The reaction given below:
C + O₂ → CO₂
The reaction above is termed a synthesis or combination reaction because two substances are combining to give a product.
- A synthesis reaction involves the formation of a single product from two or more reactants.
- The driving force for such reaction is the large and negative heat of formation of the product.
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
- After 1 half-life, the mass of the element will be 32 g.
- After 2 half-lives, the mass of the element will be 16 g.
- After 3 half-lives, the mass of the element will be 8 g.
You will want to find how many grams are in a whole mole so you know which element it is. To do this, find out how much of a mole you have.
4.95 x 10^23 atoms / 6.022 x 10^23 atoms (one whole mole of any element) = .8219860511 or ~82% of 1 mole
Now we know that, find what to multiply 20 g by to get the rest of the mole.
1 mole / .8219860511 mole = 1.216565657
20 g x 1.216565657 = ~24.33 g / mol
Now that you have grams per mole, you can look at the periodic table and the molar masses to see which this number is closely aligned.
Your answer is Magnesium (Mg), which has a molar mass of 24.305 g
Barium has a 2+ charge as it is in group 2 in the periodic table and so it has two electrons in its outer shell and chloride has a -1 charge on its chloride ion. So we will need two of the chloride ions as we have a 2+ charge to match the amount of charge on one barium ion- forming barium ion
BaCI2
