Complete question is;
Chemical reactivity of alkali metals increases down the group while reactivity of halogens decreases down the group. Give reasons
Answer:
Explained below
Explanation:
Alkali metals exhibit reactivity due to their electropositivity. Now, for alkalis, their electro-positivity increases down their group. Since their reactivity increases with increase in electropositivity, it means their reactivity also increases down the group.
Whereas, the reactivity of halogens occurs as a result of their electronegativity. Now, electronegativity for halogens decreases down the group. Since their reactivity decreases with decrease in electronegativity, it means that their reactivity will also decrease down the group.
<span>Carbon must share 4 electrons total with the the two Oxygen atoms in order to fill it's outer electron shell, and each Oxygen atom must share 2 electrons with the Carbon atom to fill their electron shells. Therefore, in total 8 electrons must be shared (4+2+2=8)</span>
As the question tells you, you need to use the formula
% mass= mass of solute/ mass of solution x 100
mass solute= 30.0 g
mass of solution= 30.0 + 270.0= 300.0 g
% mass= 30.0/ 300.0 x 100= 10%
answer is B
<h2>Complete the table to summarize the properties of the different subatomic particles. </h2>
Explanation:
Atom
It is a smallest particle which cant exist independently.
According To Dalton, atom was indivisible but later on, it was proved that atom can be subdivided into sub atomic particles called electron, proton & neutron.
These subatomic particles have marked properties .
Proton
- It was discovered by E.Goldstein .
- It is positively charged particle
- It is present in nucleus .
- Its mass is equal to 1.6726219 × 10⁻²⁷ kilograms
Neutron
- It was discovered by E.chadwick .
- It is neutral
- It is present inside the nucleus .
- It's mass is equal to 1.674927471×10⁻²⁷ kg
Electron
- It was discovered by J.J Thomson .
- It has negative charge .
- It's mass is equal to 9.10938356 × 10⁻³¹ kilograms
- It is present outside the nucleus in shells .
