Answer:
1. 1.72 moles of potassium.
2. All of the answers are true
3. Are used up during a reaction
Explanation:
Recall that the number of moles is obtained from;
Number of moles= Mass of potassium/ molar mass of potassium
Mass of potassium= 67 g
Molar mass of potassium= 39 gmol-1
Number of moles of K= 67 g/ 39 gmol-1
Number of moles = 1.72 moles of potassium.
2. When we look at all the options, we will realize that all the options are true. The rate of reaction doubles for each 10°C rise in temperature, increasing reactant concentration increases particle collision and ultimately increases the rate of reaction. Rate of reaction deals with rate of disappearance of reactants or rate of appearance of products.
3. Catalysts remain unchanged in a chemical reaction because they do not actually participate in the reaction. Hence they are not used up in any chemical reaction.
Answer:
Y³⁻ A non metal that gained three electrons.
V²⁺ A metal that lost two electron
Z²⁻ A non metal that gained two electrons
X³⁺ A metal that lost three electrons
Explanation:
Metals lost the electrons and form cation
while non metals gain the electrons and form anion.
Y³⁻
c) A non metal that gained three electrons.
Non metal gain three electrons and form anion with the charge of -3.
V²⁺
a) A metal that lost two electron
A metal lost two electrons and form cation with charge of +2.
Z²⁻
d) A non metal that gained two electrons
A non metal that gained two electrons and form anion with charge of -2.
X³⁺
b) A metal that lost three electrons
A metal that lost three electrons and form cation with charge of +3.
Answer:
the size of Ca is the greatest ,then Mg is the greater on size than Be
Explanation:
if you make the electron configuration for each of the elements, what is the main difference u gonna see ?
Be 4 1s2/2s2
Mg 12 1s2 /2s2 2p6/3s2
Ca 20 1s2 /2s2 2p6/3s2 3p6 3d/4s2
see that all the elements are in the same group but are in different period
u gonna see the last electron valance shell in Ca are too far from its nucleus but in Be the last electrons are too close and more attracted to the atom's nucleus , so the size of Ca is the biggest then Mg then Be
Answer:
The circular path and electron revolves around the nucleus in an atom is called shell or orbit.