Question

incorrect
(b)
In the following questions a statement of assertion followed by a statement of reason of given. Ch
correct answer out of the following choices.
a) Both assertion and reason are correct statements, and reason in the correct explanation of the
assertion.
b) Both assertion and reason are correct statements, but reason is not the correct explanation of
assertion
c) Assertion is correct but reason is correct statement.
pred
d) Both assertion and reason-are wrong statements
18. Assertion : Li, Na, K forms a Dobereiner traids
Reason: The average of the atomic masses of Li and K is roughly equal to the atomic mass of Na
19. Assertion : Law of octaves was applicable only upto calcium.
Keason: After calcium there is no eight elements
20. Assertion. To study the relationship between atomic mass and chemical properties. Mendeleev
concentrated on compounds formed by elements with hydrogen and oxygen.
found the atmosphere
21. Assertion : Mendeleev left some gaps in his periodic table
Reason: These gaps are defects found in his periodic table
22 Assertion : Noble gases like helium (He), neon (Ne) are discovered very late.
Reason: Noble gases are very inert and their concentrations in the atmosphere are very low.
23. Asserdion : Mendeleev left spaces for isotopes of various elements.
d Reason: Isotopes have similar chemical properties, but different atomic masses.
24. Assertion: Fluorine () and chlorine (CI) have the same number of velence electrons.
Reason: Both belong to the same group, group 17
25. Assertion : Atomic radius in general decrease along a period
Reason: In a period effective nuclear charges decrease
26. Assertion : Metallic character of elements generally increase along a period
Reason: Atomic number increase along a period
27 Assertion : Non metallic character of elements increase down the group
Reason: Elfective nuclear change increase down the group
6​

Answer 1

Answer:

Hello please follow my another id which is kanak792