Chemistry
Assertion (A): Group 17 elements are known as alkaline earth metals.
Reason (R): Group 17 elements are salt formers.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Periodic Table
4 Likes
Answer
A is false but R is true.
Explanation — Group 17 elements are known as halogens. Hence the assertion (A) is false.
Halogen name is derived from combination of greek word halo meaning sea or salt and gen meaning producing. Therefore, group 17 elements are salt formers. Hence the reason (R) is true.
Answered By
2 Likes
Related Questions
Assertion (A): Hydrogen can be placed in two groups i.e., with Alkali metals and with halogens.
Reason (R): Hydrogen has two electrons in its valence shell.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Cobalt (atomic mass 58.94) is placed before Nickel (atomic mass 58.68) in Mendeleev's periodic table.
Reason (R): Physical and chemical properties of the elements are a periodic function of their atomic masses.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Match column A with column B
Column A Column B (a) Elements short by 1 electron in octet (i) Transition elements (b) Highly reactive elements (ii) Noble gases (c) Non-reactive elements (iii) Alkali metals (d) Elements of group 3 to 12 (iv) Alkaline earth metals (e) Radioactive elements (v) Halogens (f) Elements with 2 electrons in the outermost orbit (vi) Actinides Write down the word that will correctly complete the following sentences:
(a) Relative atomic mass of a light element up to calcium is approximately …………… its atomic number.
(b) The horizontal rows in a periodic table are called ……………
(c) Going across a period left to right, atomic size ……………
(d) Moving left to right in the second period, number of valence electrons ……………
(e) Moving down in the second group, number of valence electrons ……………