Atomic Mass of the mainly occurring isotopes) of the first 20 elements (rounded figures)
Ordering on atomic number 1 - 20
1 H
4 He
7 Li
9 Be
11 B
12 C
14 N
16 O
19 F
20 Ne
23 Na
24 Mg
27 Al
28 Si
31 P
32 S
35.5 Cl
36 Ar
39 K
40 Ca
*) But actually there are about 85 'different mass' isotopes from these 20 elements.
The atomic numbers of the first 20 elements are:
The Atomic number is the number of protons (positive charges) in the nucleus. So the very simple answer is Hydrogen has 1 proton, so Atomic number is 1 all the way up to Calcium, 20 protons with Atomic number 20. The significant fact here is that the atomic number defines the element.
These are the atomic mass values of the first 20 atoms, numbered 1 to 20:
This question can be answered by any Periodic Table. The atomic number is the number of protons in the nucleus of an atom of that particular element. The atomic number must be a counting number (1,2,3,4...) and the atomic number increases by increments of one from left to right across each row. The sequence is continued of the next row, for instance neon's atomic number is 10, the next row starts with sodium; atomic number 11.
Hydrogen: 0 Helium: 2 Lithium: 4 Beryllium: 5 Boron: 6 Carbon: 6 Nitrogen: 7 Oxygen: 8 Fluorine: 10 Neon: 10 Sodium: 12 Magnesium: 12 Aluminum: 14 Silicon: 14 Phosphorus: 16 Sulfur: 16 Chlorine: 18 Argon: 22 Potassium: 20 Calcium: 20
The number of neutrons in an element is not fixed. This is why "isotopes" of elements exist. Take the simplest atom, that of Hydrogen, this can have 0, 1 or 2 neutrons.
Thus you can see that your question is far to broad to elicit a simple answer.
Starting from
Hydrogen (H) atomic number 1
Helium (He) atomic number 2
Lithium (Li) atomic number 3
Beryllium (Be) atomic number 4
Boron (B) atomic number 5
Carbon (C) atomic number 6
Nitrogen (N) atomic number 7
Oxygen (O) atomic number 8
Fluorine (F) atomic number 9
Neon (Ne) atomic number 10
Sodium (Na) atomic number 11
Magnesium (Mg) atomic number 12
Aluminum (Al) atomic number 13
Silicon (Si) atomic number 14
Phosphorus (P) atomic number 15
Sulfur (S) atomic number 16
Chlorine (Cl) atomic number 17
Argon (Ar) atomic number 18
Potassium (K) atomic number 19
Calcium (Ca) atomic number 20.
Hydrogen: 1 proton
Helium: 2 protons
Lithium: 3
Beryllium: 4
Boron: 5
Carbon: 6
Nitrogen: 7
Oxygen: 8
Fluorine: 9
Neon: 10
Sodium: 11
Magnesium: 12
Aluminum: 13
Silicon: 14
Phosphorus: 15
Sulfur: 16
Chlorine: 17
Argon: 18
Potassium: 19
Calcium: 20
Mass numbers refer to the numbers of protons and neutrons in the nuclei of specific isotopes. It would be easier to ask for the atomic weights of the first 20 elements on the periodic table, because they are written along with element's symbol and atomic number. If you really want to know the mass numbers of the isotopes of the first 20 elements, I recommend looking up the Wikipedia article for each element.
I'm unable to graph atomic radii in this text-based format. However, you can find data on atomic radii for the first 20 elements in a periodic table resource or chemistry textbook. Atomic radii generally decrease across a period from left to right and increase down a group from top to bottom.
The mass numbers of the first 20 elements from hydrogen (1) to calcium (20) are as follows: 1 (H), 4 (He), 7 (Li), 9 (Be), 11 (B), 12 (C), 14 (N), 16 (O), 19 (F), 20 (Ne), 23 (Na), 24 (Mg), 27 (Al), 28 (Si), 31 (P), 32 (S), 35 (Cl), 40 (K), 39 (Ca).
The oxidation numbers for the first 20 elements in the periodic table are typically as follows: Group 1 elements: +1; Group 2 elements: +2; Group 13 elements: +3; Group 14 elements: +4 or -4; Group 15 elements: -3; Group 16 elements: -2; Group 17 elements: -1; Group 18 elements: 0. Keep in mind that oxidation numbers can vary in different compounds and contexts.
We would find it easier to respond to this question if we knew what is meant by the 'top 20 elements'.
Conductors in the first twenty elements include; Lithium - Li Beryllium - Be Carbon - C Sodium - Na Magnesium - Mg Silicon - Si Potassium - K Calcium - Ca
I'm unable to graph atomic radii in this text-based format. However, you can find data on atomic radii for the first 20 elements in a periodic table resource or chemistry textbook. Atomic radii generally decrease across a period from left to right and increase down a group from top to bottom.
The mass numbers of the first 20 elements from hydrogen (1) to calcium (20) are as follows: 1 (H), 4 (He), 7 (Li), 9 (Be), 11 (B), 12 (C), 14 (N), 16 (O), 19 (F), 20 (Ne), 23 (Na), 24 (Mg), 27 (Al), 28 (Si), 31 (P), 32 (S), 35 (Cl), 40 (K), 39 (Ca).
Elements by definition are electrical neutral and therefore are not cations, which have a positive electrical charge. The first (i.e., those having the lowest atomic numbers) 20 elements that commonly form cations during chemical reaction are hydrogen, lithium, beryllium, sodium, magnesium, aluminum, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, and arsenic.
Yes, it has the atomic # of 20 on the periodic table of elements.
The oxidation numbers for the first 20 elements in the periodic table are typically as follows: Group 1 elements: +1; Group 2 elements: +2; Group 13 elements: +3; Group 14 elements: +4 or -4; Group 15 elements: -3; Group 16 elements: -2; Group 17 elements: -1; Group 18 elements: 0. Keep in mind that oxidation numbers can vary in different compounds and contexts.
Neon is a non meta element. Atomic mass of it is 20 Atomic number of it is1 180.
Dalton only listed 20 elements in his table because in his atomic theory, he believed that all elements could be explained in terms of simple ratios of the first 20 elements. At the time, only 20 elements were known and studied in depth, so Dalton's table reflected the knowledge available to him.
We would find it easier to respond to this question if we knew what is meant by the 'top 20 elements'.
The first 20 odd numbers are: 13579111315171921232527293133353739.
Conductors in the first twenty elements include; Lithium - Li Beryllium - Be Carbon - C Sodium - Na Magnesium - Mg Silicon - Si Potassium - K Calcium - Ca
Took me a while to find but you can spot it eventually. It's Argon (Ar) and Potassium (K). Hope this helps :)
20 kilotons