The statement is true. The octet rule refers to the general rule of thumb wherein atoms of main-group elements tend to bond with other atoms in such a way that each atom possesses eight electrons (octet) in their valence shell. They tend to form the same electronic configuration as the noble gases. However, there are some exceptions to this rule. One of which is silane, SiH₄. A hydrogen atom only has 1 valence electron and needs another electron to complete its energy level. This is unlike other atoms, for example, carbon which has 4 valence electrons and needs to form 4 covalent bonds to fill its energy levels. Thus, 4 hydrogen atoms need only 4 more electrons. This is given by the silicon atom which has 4 valence electrons. Therefore, when a silicon atom is bonded to 4 hydrogen atoms, the resulting molecule, SiH₄, is a stable one.
Once you balance the enquation you "switch partners" of the element (negative charge to positive charge)
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Answer:</h3>
2.47 × 10^24 molecules
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Explanation:</h3>
One mole of a compound contains molecules equivalent to the Avogadro's number, 6.022 × 10^23.
That is, 1 mole of a compound = 6.022 × 10^23 molecules
Therefore,
1 mole of Na₂CO₃ = 6.022 × 10^23 molecules
Thus, we can calculate the number of molecules in 4.1 moles of Na₂CO₃
we get,
= 4.1 moles × 6.022 × 10^23 molecules
= 2.47 × 10^24 molecules
Hence, 4.1 moles of Na₂CO₃ contains 2.47 × 10^24 molecules
Answer:
= 29.64 g NaNO3
Explanation:
Molarity is given by the formula;
Molarity = Moles/Volume in liters
Therefore;
Number of moles = Molarity × Volume in liters
= 1.55 M × 0.225 L
= 0.34875 moles NaNO3
Thus; 0.34875 moles of NaNO3 is needed equivalent to;
= 0.34875 moles × 84.99 g/mol
= 29.64 g
