The nucleus of a atom contains the protons and the neutrons all most all of the atoms mass is weigh by the protons and the neurons.
Lar mass of Ca<span> = 40.08 </span>grams/mole 77.4 g Ca<span> * ( 1 </span>mole Ca<span>/ 40.08 ... n = m / M 1mol </span>Ca<span>weights 40 gmol-1 n = 77,4 / 40 = 1.93 </span>mol<span>.</span>
Answer:
chemicals symbols are used for abbreviating the name of the element/chemical while chemicals formulas tell you how much of each element are in each chemical atom
Explanation:
<span>Ionic bonding is the entire exchange of valence electron(s) between particles. It is a kind of substance security that creates two oppositely charged particles. In ionic bonds, the metal loses electrons to wind up plainly an emphatically charged cation, though the nonmetal acknowledges those electrons to end up noticeably a contrarily charged anion.</span>
Answer:

Explanation:
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In this case, considering that the mass of hydrazine is missing, we can assume it is 130.0 g (a problem found on ethernet). In such a way, since we need a mass-mole-atoms relationship by which we can compute moles of hydrazine given its molar mass (32.06 g/mol), then the moles of hydrogen considering one mole of hydrazine has four moles of hydrogen and one mole of hydrogen has 6.022x10²³ atoms (Avogadro's number); therefore, we proceed as shown below:

Notice 130.0 g has four significant figures, therefore the result is displayed with four as well.
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