Certain naturally occurring radioactive isotopes are unstable: Their nucleus breaks apart, undergoing nuclear decay. ... All elements with 84 or more protons are unstable; they eventually undergo decay. Other isotopes with fewer protons in their nucleus are also radioactive.
Answer:
Mass number is defined as the number of protons plus the number of neutrons.
Explanation:
Every atom of an element have proton(s), neutron(s) and electron(s). The proton number of an element is the atomic number of that element. For an electronically neutral atom the proton number is equal to the electron numbers. The neutron and the proton contributes to the mass of every atom. The electron is more active when atoms are bonding.
Mass number of an element is the number of proton plus the number of neutron.
Atomic number of an atom is the number of proton present, so it can never be atomic number.
Isotopy talks about same element having different number of neutron but same number of protons in each atom. Example is hydrogen that exist as protium, deuterium and tritium. It cannot be isotopic number.
Ionic number talks about elements that possess a charge. The elements have been ionized.
The answer is Mass number because the sum of proton number and neutron number is equals to mass number.
Hello!
* First Step: to know Avogrado's Law
We know that by the Law of Avogrado, for each mole of substance we have 6.02*10²³ atoms, if:
** Second Step: to know the molar mass of the solute
The molar mass of of magnesium = 24.30 g/mol
*** Third step: make the ratio mass / mol with atoms
1 mol we have 6.02*10²³ atoms
1 mole of Mg we have 24.30 g
Then we have:
24.30 g ------------- 6.02*10²³ atoms
x ----------------------- 6.98*10^24 atoms

multiply cross




I Hope this helps, greetings ... DexteR! =)
<span>Metals are usually good conductors because they have abundant free negative charges, or electrons.
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The answer is Copper
Answer:
A is Carbon atom ; B is Nitrogen C is Nitrogen D is oxygen
Explanation:
A is is isotope of Carbon atom with proton 6 electrons and 8 neutrons, B is Nitrogen atom with 7 protons and 7 neutrons, C is Isotope of Nitogen with 7 protons and 8 neutrons and D is isotope of oxygen with 8 protons and 7 neutrons.