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Mass number is term used for isotopes, not for elements.
And it is boring to list here all the isotopes of the first 20 elements.
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∙ 11y ago
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Oxidation number for first 20 elements?
H -->+1 He --> 0 Be --> B
What element has a mass number of 21 and an atomic number of 10?
Sc, scandium (21), the first metal element in the 3d-block (transition elements); next to calcium (20).
What is the mass number of neon-20?
The mass number of a conventionally named isotope is the number after the hyphen; in this instance, 20.
How many protons electrons and neutrons does an atom with atomic number 20 and a mass number 45 contain?
Atomic number 20 therefore 20 protons and 20 electrons. Mass number 45 therefore 45-20 = 25 neutrons.
What is the atomic number and the mass number of an element with 20 atomic number and 23 mass number?
Sodium is a metal element. Atomic mass number of it is 23.
What are the first 20 elements of the periodic table along with their mass number?
see related link
Oxidation number for first 20 elements?
H -->+1 He --> 0 Be --> B
What is the mass number of neon-20?
The mass number of a conventionally named isotope is the number after the hyphen; in this instance, 20.
What element has a mass number of 21 and an atomic number of 10?
Sc, scandium (21), the first metal element in the 3d-block (transition elements); next to calcium (20).
How many protons electrons and neutrons does an atom with atomic number 20 and a mass number 45 contain?
Atomic number 20 therefore 20 protons and 20 electrons. Mass number 45 therefore 45-20 = 25 neutrons.
What is the atomic number and the mass number of an element with 20 atomic number and 23 mass number?
Sodium is a metal element. Atomic mass number of it is 23.
Number of elements know in 1800?
Approx. 20 elements were known in 1800.
What is the mass number for Argon-37?
You actually just answered your own question. The Isotope Ar-37 has a mass of 37. Most elements and Isotopes are commonly phrased like "Element-Mass"
How many neutrons does potassium-39 have?
Answer: 20 Details: mass number - atomic number = number of neutrons.
What are the 20 lightest elements?
The first 20 elements are Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen,Oxygen, Flourine,Neon,Sodium,Magnesium, Aluminium,Silicon,Phosporous,Sulphur, Chlorine, Argon, Pottasium, and Calcium. The numbers on the top right are the mass of the element.
What elements mass is 30 and a noble gas but not neon?
There is no such noble gas with an atomic mass of 30. The mass of neon is 20 and the mass of the next noble gas, argon, is 40
What are the first 20 elements at room temperature?
H
