Answer:
O, S, Se, Te, Po
Explanation:
Oxygen, sulphur, selenium, tellurium and polonium are all members of group sixteen. The elements in group sixteen all possess six electrons in their outermost shell. Recall that an atom is said to stable if it contains eight electrons in its outermost shell. This is also referred to as the octet rule. Hence atoms of elements obey the octet rule when they combine to form compounds with eight electrons present on the outermost shell of each atom.
Having six electrons on their outermost shell implies that they need to gain two electrons by bonding to other atoms of other elements. Two examples will suffice here.
Water is formed when an oxygen atom shares an electron with each hydrogen atoms.
Hydrogen sulphide is formed when sulphur share two electrons with two hydrogen atoms. Hence the answer.
Answer:
Sample A - mixture
Sample B- Mixture
Explanation:
Looking at sample A, we can see that as water was poured over sample A, the sample was separated into its components as the powder disappeared leaving behind a gritty black sand-like material on the surface of the paper. A separation of the mixture has taken place.
In sample B, we can clearly see that it is a mixture because the amount of solid recovered is much less than the total mass of the solid put into the beaker. The sample must have been separated into its components.
When CH₄ is burnt in excess O₂ following products are formed,
CH₄ + 2 O₂ → CO₂ + 2 H₂O
According to equation 1 mole of CH₄ (16 g) reacts with 2 moles of O₂ to produce 1 mole of CO₂ and 2 moles of H₂O. Hence the products are,
1 mole of CO₂ and 2 moles of H₂O
Converting 1 mole CO₂ to grams;
As,
Mass = Moles × M.mass
Mass = 1 mol × 44 g.mol⁻¹
Mass = 40 g of CO₂
Converting 2 moles of H₂O to grams,
Mass = 2 mol × 18 g.mol⁻¹
Mass = 36 g of H₂O
Total grams of products;
Mass of CO₂ = 44 g
+ Mass of H₂O = 36 g
-------------
Total = 80 g of Product
Result:
80 grams of product is formed when 16 grams of CH₄ is burnt in excess of Oxygen.
Answer:
0.00032 Grams of NaCl per 1 gram of the solution
Explanation:
