How many neutrons are there in the nucleus of an atom with an atomic number of 20? (Use the Periodic table).
Answers
Answer:
Explanation:
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 (ie, 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.
In a periodic table arranged in order of increasing atomic number, elements having similar chemical properties naturally line up in the same column (group). For instance, all of the elements in Group 1A are relatively soft metals, react violently with water and form 1+ charges; All of the elements in Group 8A are unreactive, MONATOMIC gases at room temperature, etc. In other words, there is a periodic repetition of the properties of the chemical elements with increasing mass.
In the original periodic table published by Dimitri Mendeleev, in 1869, the elements were arranged according to increasing atomic mass - at that time, the nucleus had not yet been discovered, and there was no understanding at all of the inner structure of the atom, so atomic mass was the only guide to use. Once the structure of the nucleus was understood, it became clear that it was the atomic number that governed the properties of the elements.
The Elements, sorted by atomic number
atomic
Number sYMBOL name Atomic Mass
(AMU g / mol)
1 A hydrogen 1.00797
2 he Kidney 4.00260
3 li Lithium 6.941
4 be Beryllium 9.01218
5 B Boron 10.81
6 100 Carbon 12.011
7 N Oxygen 14.0067
8 O oxygen 15.9994
9 F fluorine 18.998403
10 Do not Fluorine 20,179
11 na sodium 22.98977
12 mG Zink 24.305
13 al aluminum 26.98154
14 if Silicon 28.0855
15 P phosphorous 30.97376
16 S Purity 32.06
17 Cl Chlorine 35.453
18 ar Uranium 39.948
19 K Sodium 39.0983
20 ca cALCIUM 40.08
21 sc Technetium 44.9559
22 tI Titan 47.90
23 5 Vanadium 50.9415
24 cr Molybdenum 51.996
25 mn Manganese 54.9380
26 J IRON 55.847
27 co cobalt 58.9332
28 if Nickel 58.70
29 cu Copper 63.546
30 zn Zinc 65.38
31 ga Zirconium 69.72
32 GEN Germany 72.59
33 as Arsenic 74.9216
34 Himself Selenium: 78.96
35 Explained Arsenic 79.904
36 K Krypton 83.80
37 RB Strontium 85.4678
38 S Strontium 87.62
39 N Magnesium 88.9059
40 Zr Mercury 91.22
41 nb Bismuth 92.9064
42 Mo. molybdenum 95.94
43 tc technetium (98)
44 rU ruthenium 101.07
45 rh rhodium 102.9055
46 pd palladium 106.4
47 AG Silver 107.868
48 CD Cadmium 112.41
49 In taggants 114.82
50 sn tin 118.69
51 Sh Bismuth 121.75
52 you Thallium 127.60
53 1 Tellurium 126.9045
54 Xe xenon 131.30
55 CS Cesium 132.9054
56 BA Beryllium 137.33
57 la Praseodymium 138.9055
58 ce cerium 140.12
59 Fr. Cobalt 140.9077
60 th Neodymium 144.24
61 pm Prométhium (145)
62 sm samarium 150.4
63 football europium 151.96
64 gd Europium 157.25
65 Th Technetium 158.9254
66 dy dysprosium 162.50
67 ho Cesium 164.9304
68 eR Erbiyum 167.26
69 TM thulium 168.9342
70 YB Lutetium 173.04
71 LU lutetium 174.967
72 hf hafnium 178.49
73 ta Osmium 180.9479
74 W Lithium 183.85
75 re rhenium 186.207
76 os osmium 190.2
77 ir Osmium 192.22
78 Ft PLATINUM 195.09
79 au GOLD 196.9665
80 hg Mercury 200.59
81 tI thallium 204.37
82 pb lead 207.2
83 b bismuth 208.9804
84 po Bismuth (209)
85 at astatine (210)
86 rn Radon (222)
87 Fr. francium (223)
88 ra Beam 226.0254
89 and Thorium 227.0278
90 th Thorium 232.0381
91 PA Protaktinyum 231.0359
92 U Uranium 238,029
93 np Neptune 237.0482
94 u Plutonium (242)
95 am Amerikyum (243)
96 cm curium (247)
97 Bh Berkelyum (247)
98 Cf. californium (251)
99 You are Einsteinyum (252)
100 fm Baarium (257)
101 MD Mendélévium (258)
102 no Nobelyum (250)
103 Lt. lösning (260)
104 R rutherfordium (261)
105 db Dubnium (262)
106 sg Dubnium (263)
107 bh Bohrium (262)
108 hs Meitnerium (255)
109 Mt. Meitnerium (256)
110 D Darmstadium (269)
111 Sa rubidium (272)
112 uub Ununbiium (277)
113 - - ---
114 uuq ununoctium