Answer:
56
Explanation:
The mass number of an atom is a sum of its number of protons and neutrons. Iron (Fe) has an atomic number of 26. This means that it has 26 protons. Since we know it has 26 protons and are told it has 30 neutrons. The mass number of this atom of Iron is 26+30 = 56
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Covalent compounds are formed when non metals bond together.
Answer:
No. of electrons of the element
VB theory does not indicate that the diatomic molecule He₂ is a viable species.
Helium has atomic number 2, it has 2 protons and 2 electrons.
Electron configuration of helium atom: ₂He 1s².
Helim (He) is a noble gas.
Noble gases (group 18) are in group 18: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). They have very low chemical reactivity.
Noble gases have very stable electron configuration and does not need to gain electrons, only when they gain energy.
Valence bond (VB) theory explains chemical bonding.
Helium atom is stable and does not form molecule.
More about valence bond (VB) theory: brainly.com/question/23129240
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