Atoms of an element ¹⁹A readily with those of another element, ²⁷B.
⁹ ¹³
Which group of the periodic table does atom A belong to ?
Answers
Atomic Numbers
1A 2A 3A 4A 5A 6A 7A 8A
(1) (2) (13) (14) (15) (16) (17) (18)
3B 4B 5B 6B 7B — 8B — 1B 2B
(3) (4) (5) (6) (7) (8) (9) (10) (11) (12)
1 1 2
2 3 4 5 6 7 8 9 10
3 11 12 13 14 15 16 17 18
4 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
5 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
6 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
7 87 88 89 104 105 106 107 108 109 110 111 112 — 114 — — — —
6 58 59 60 61 62 63 64 65 66 67 68 69 70 71
7 90 91 92 93 94 95 96 97 98 99 100 101 102 103
In the modern periodic table, the elements are listed in order of increasing atomic number. The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present). The number of protons determines how many electrons surround the nucleus, and it is the arrangement of these electrons that determines most of the chemical behavior of an element.