which has the lower atomic number?
The mass number is defined as the sum of the number of protons and neutrons according to the following mathematical equation:
Mass number = number of protons + number of neutrons and is indicated by the symbol (A), as the mass number in the periodic table is placed below the element, but when expressing the element, the mass number is placed to the left of the element so that it is expressed by a small number above the element.
It is worth noting that the mass of electrons is not included in the calculation of the mass number, because their mass is very small, and is approximately 1,800 times smaller than the mass of a proton, and the mass number of any atom is equal to the atomic mass, rounded to the nearest integer, in addition to that the different isotopes of the same element are They have different mass numbers, because they contain different numbers of neutrons.
which has the lower atomic number?
2 Helium He
3 Lithium Li
4 Beryllium Be
5 Boron B
6 Carbon C
7 Nitrogen N
8 Oxygen O
9 Fluorine F
10 Neon Ne
11 Sodium Na
12 Magnesium Mg
13 Aluminum Al
14 Silicon Si
15 Phosphorus P
16 Sulfur S
17 Chlorine Cl
18 Argon Ar
19 Potassium K
20 Calcium Ca
21 Scandium Sc
22 Titanium Ti
23 Vanadium V
24 Chromium Cr
25 Manganese Mn
26 Iron Fe
27 Cobalt Co
28 Nickel Ni
29 Copper Cu
30 Zinc Zn
31 Gallium Ga
32 Germanium Ge
33 Arsenic As
34 Selenium Se
35 Bromine Br
36 Krypton Kr
37 Rubidium Rb
38 Strontium Sr
39 Yttrium Y
40 Zirconium Zr
41 Niobium Nb
42 Molybdenum Mo
43 Technetium Tc
44 Ruthenium Ru
45 Rhodium Rh
46 Palladium Pd
47 Silver Ag
48 Cadmium Cd
49 Indium In
50 Tin Sn
51 Antimony Sb
52 Tellurium Te
53 Iodine I
54 Xenon Xe
55 Cesium Cs
56 Barium Ba
57 Lanthanum La
58 Cerium Ce
59 Praseodymium Pr
60 Neodymium Nd
61 Promethium Pm
62 Samarium Sm
63 Europium Eu
64 Gadolinium Gd
65 Terbium Tb
66 Dysprosium Dy
67 Holmium Ho
68 Erbium Er
69 Thulium Tm
70 Ytterbium Yb
71 Lutetium Lu
72 Hafnium Hf
73 Tantalum Ta
74 Tungsten W
75 Rhenium Re
76 Osmium Os
77 Iridium Ir
78 Platinum Pt
79 Gold Au
80 Mercury Hg
81 Thallium Tl
82 Lead Pb
83 Bismuth Bi
84 Polonium Po
85 Astatine At
86 Radon Rn
87 Francium Fr
88 Radium Ra
89 Actinium Ac
90 Thorium Th
91 Protactinium Pa
92 Uranium U
93 Neptunium Np
94 Plutonium Pu
95 Americium Am
96 Curium Cm
97 Berkelium Bk
98 Californium Cf
99 Einsteinium Es
100 Fermium Fm
101 Mendelevium Md
102 Nobelium No
103 Lawrencium Lr
104 Rutherfordium Rf
105 Dubnium Db
106 Seaborgium Sg
107 Bohrium Bh
108 Hassium Hs
109 Meitnerium Mt