Question

1. which of these elements has atoms with the largest atomic radius?

a. sr
b. cs
c. ba
d. rb

1. which sequence correctly places the elements in order of increasing ionization energy?

a. h→be→al→ga
b. i→br→cl→f
c. h→li→na→k
d. o→s→se→te

1. in which period of the periodic table is the element with the highest electronegativity found?

a. period 1
b. period 2
c. period 3
d. period 4

1. how many va belonging to the n

a. 1
b. 3
c. 7
d. 8

1. how many valence (si) have?

a. 2
b. 4
c. 3
d. 6

1. element x has 2 valence e element is it most like?

a. beryllium
b. flourine
c. neon
d. phosphorus

Explanation:

1. Atomic radius increases down a group and decreases across a period. Cs (Cesium) is in Group 1 and Period 6, which is further down the group compared to the other elements (Sr - Group 2 Period 5, Ba - Group 2 Period 6, Rb - Group 1 Period 5).
2. Ionization energy increases across a period and decreases down a group. In option B (I → Br → Cl → F), as we move up the group (from I to F in Group 17), ionization energy increases.
3. Fluorine (in Period 2) has the highest electronegativity.
4. Silicon (Si) has an electron configuration of \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{2}\). The valence electrons are in the 3rd shell (\(3s^{2}3p^{2}\)), so there are 4 valence electrons.
5. Elements with the same number of valence electrons are similar. Beryllium (Be) has 2 valence electrons (like Element X).

Answer:

1. B. Cs
2. B. \(I

ightarrow Br
ightarrow Cl
ightarrow F\)

1. B. Period 2
2. B. 4
3. A. Beryllium