We remember from our school chemistry course that every element has its own specific atomic number. It is the same as the number of protons that the atom of each element has, so sometimes atomic number is called proton number. It is always the whole number and it ranges from 1 to 118, according to the number of the element in the Periodic Table. This number can be really important and something essential to know, in relation to a certain chemical element which is the issue of our interest at the moment.

Why is this so? Why is the atomic number so important? First of all, it is the number that makes elements different from one another as it shows the number of protons in their nuclei. Also, knowing the atomic number of an element can give us an idea about the position of the element in the Periodic Table. Atomic number of an element never changes: for example, the atomic number of oxygen is always 8, and the atomic number of Chlorine is always 18. The atomic number is marked with the symbol Z, taken from a German word zahl (or atomzahl, which is 'atomic number' in German).

An element's atomic number is the number of protons in the nucleus of a single atom of that element. The atomic number of an element or isotope cannot change, so you can use the atomic number to help figure out other characteristics, such as the number of electrons and neutrons in an atom. Part 1 Finding the Atomic Number. The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D).The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.

This website is created for those who need to know the atomic number of a central chemical element. By using our website, you can do it in just one click and receive short and correct information on this matter. There is also some extra summary on every each chemical element which can be found at our website, including the atomic weight of each element, as well as physical and chemical properties of every element and its importance. Use this website at any time when you need to get fast and precise information about atomic or proton number of chemical elements.

List of chemical elements in periodic table with atomic number, chemical symbol and atomic weight. You can sort the elements by clicking on the table headers. Please click on the element name for complete list of element properties.

Atomic Number	Chemical Symbol	Element Name	Atomic Weight (u)
1	H	Hydrogen	1.008
2	He	Helium	4.003
3	Li	Lithium	6.94
4	Be	Beryllium	9.012
5	B	Boron	10.81
6	C	Carbon	12.011
7	N	Nitrogen	14.007
8	O	Oxygen	15.999
9	F	Fluorine	18.998
10	Ne	Neon	20.18
11	Na	Sodium	22.99
12	Mg	Magnesium	24.305
13	Al	Aluminium	26.982
14	Si	Silicon	28.085
15	P	Phosphorus	30.974
16	S	Sulfur	32.06
17	Cl	Chlorine	35.45
18	Ar	Argon	39.948
19	K	Potassium	39.098
20	Ca	Calcium	40.078
21	Sc	Scandium	44.956
22	Ti	Titanium	47.867
23	V	Vanadium	50.942
24	Cr	Chromium	51.996
25	Mn	Manganese	54.938
26	Fe	Iron	55.845
27	Co	Cobalt	58.933
28	Ni	Nickel	58.693
29	Cu	Copper	63.546
30	Zn	Zinc	65.38
31	Ga	Gallium	69.723
32	Ge	Germanium	72.63
33	As	Arsenic	74.922
34	Se	Selenium	78.971
35	Br	Bromine	79.904
36	Kr	Krypton	83.798
37	Rb	Rubidium	85.468
38	Sr	Strontium	87.62
39	Y	Yttrium	88.906
40	Zr	Zirconium	91.224
41	Nb	Niobium	92.906
42	Mo	Molybdenum	95.95
43	Tc	Technetium	98
44	Ru	Ruthenium	101.07
45	Rh	Rhodium	102.906
46	Pd	Palladium	106.42
47	Ag	Silver	107.868
48	Cd	Cadmium	112.414
49	In	Indium	114.818
50	Sn	Tin	118.71
51	Sb	Antimony	121.76
52	Te	Tellurium	127.6
53	I	Iodine	126.904
54	Xe	Xenon	131.293
55	Cs	Caesium	132.905
56	Ba	Barium	137.327
57	La	Lanthanum	138.905
58	Ce	Cerium	140.116
59	Pr	Praseodymium	140.908
60	Nd	Neodymium	144.242
61	Pm	Promethium	145
62	Sm	Samarium	150.36
63	Eu	Europium	151.964
64	Gd	Gadolinium	157.25
65	Tb	Terbium	158.925
66	Dy	Dysprosium	162.5
67	Ho	Holmium	164.93
68	Er	Erbium	167.259
69	Tm	Thulium	168.934
70	Yb	Ytterbium	173.045
71	Lu	Lutetium	174.967
72	Hf	Hafnium	178.49
73	Ta	Tantalum	180.948
74	W	Tungsten	183.84
75	Re	Rhenium	186.207
76	Os	Osmium	190.23
77	Ir	Iridium	192.217
78	Pt	Platinum	195.084
79	Au	Gold	196.967
80	Hg	Mercury	200.592
81	Tl	Thallium	204.38
82	Pb	Lead	207.2
83	Bi	Bismuth	208.98
84	Po	Polonium	209
85	At	Astatine	210
86	Rn	Radon	222
87	Fr	Francium	223
88	Ra	Radium	226
89	Ac	Actinium	227
90	Th	Thorium	232.038
91	Pa	Protactinium	231.036
92	U	Uranium	238.029
93	Np	Neptunium	237
94	Pu	Plutonium	244
95	Am	Americium	243
96	Cm	Curium	247
97	Bk	Berkelium	247
98	Cf	Californium	251
99	Es	Einsteinium	252
100	Fm	Fermium	257
101	Md	Mendelevium	258
102	No	Nobelium	259
103	Lr	Lawrencium	266
104	Rf	Rutherfordium	267
105	Db	Dubnium	268
106	Sg	Seaborgium	269
107	Bh	Bohrium	270
108	Hs	Hassium	277
109	Mt	Meitnerium	278
110	Ds	Darmstadtium	281
111	Rg	Roentgenium	282
112	Cn	Copernicium	285
113	Nh	Nihonium	286
114	Fl	Flerovium	289
115	Mc	Moscovium	290
116	Lv	Livermorium	293
117	Ts	Tennessine	294
118	Og	Oganesson	294

Lists of Elements in Periodic Table

You can also list the elements in various ordered properties with printable tables below.

Lists of Elements by Group Number in Periodic Table

» Group 1» Group 2» Group 3» Group 4» Group 5» Group 6» Group 7» Group 8» Group 9» Group 10» Group 11» Group 12» Group 13» Group 14» Group 15» Group 16» Group 17» Group 18

Learning Objective

• Determine the relationship between the mass number of an atom, its atomic number, its atomic mass, and its number of subatomic particles

Key Points

• Neutral atoms of each element contain an equal number of protons and electrons.
• The number of protons determines an element’s atomic number and is used to distinguish one element from another.
• The number of neutrons is variable, resulting in isotopes, which are different forms of the same atom that vary only in the number of neutrons they possess.
• Together, the number of protons and the number of neutrons determine an element’s mass number.
• Since an element’s isotopes have slightly different mass numbers, the atomic mass is calculated by obtaining the mean of the mass numbers for its isotopes.

Terms

Atomic Number Is The Number Of Protons

• atomic massThe average mass of an atom, taking into account all its naturally occurring isotopes.
• mass numberThe sum of the number of protons and the number of neutrons in an atom.
• atomic numberThe number of protons in an atom.

Atomic Number

Neutral atoms of an element contain an equal number of protons and electrons. The number of protons determines an element’s atomic number (Z) and distinguishes one element from another. For example, carbon’s atomic number (Z) is 6 because it has 6 protons. The number of neutrons can vary to produce isotopes, which are atoms of the same element that have different numbers of neutrons. The number of electrons can also be different in atoms of the same element, thus producing ions (charged atoms). For instance, iron, Fe, can exist in its neutral state, or in the +2 and +3 ionic states.

Mass Number

An element’s mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number. This approximation of mass can be used to easily calculate how many neutrons an element has by simply subtracting the number of protons from the mass number. Protons and neutrons both weigh about one atomic mass unit or amu. Isotopes of the same element will have the same atomic number but different mass numbers.

Scientists determine the atomic mass by calculating the mean of the mass numbers for its naturally-occurring isotopes. Often, the resulting number contains a decimal. For example, the atomic mass of chlorine (Cl) is 35.45 amu because chlorine is composed of several isotopes, some (the majority) with an atomic mass of 35 amu (17 protons and 18 neutrons) and some with an atomic mass of 37 amu (17 protons and 20 neutrons).

Atomic Number Is 50 Crossword

Given an atomic number (Z) and mass number (A), you can find the number of protons, neutrons, and electrons in a neutral atom. For example, a lithium atom (Z=3, A=7 amu) contains three protons (found from Z), three electrons (as the number of protons is equal to the number of electrons in an atom), and four neutrons (7 – 3 = 4).

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Atomic Number Is 14

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