Answer:
- Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
- Electrons repel one another based on the VSEPR theory;
- Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.
Explanation:
The shape and the bond orientation of molecules and ions are both explained by the valences shell electron pair repulsion theory (VSEPR).
Ammonia,
, is a molecule which contains three N-H bonds, as well as one lone pair on nitrogen. According to the VSEPR theory, molecules try to acquire a shape which would minimize the repulsion exhibited by the electron clouds present, that is, between the bonding (shared in a bond) and non-bonding (lone pair) electrons.
In VSEPR, our main step is to calculate the steric number, this is the sum of the number of bonds (ignoring the multiplicity of any bond) and the lone pairs on a central atom. In ammonia, we have 3 bonds and 1 lone pair, totaling to a steric number of 4. A steric number of 4 without any lone pairs on a central atom and just bonds would yield a tetrahedral shape with bond angles of
.
Now, in this case, since we have a lone pair instead of a bond, it is repelling stronger decreasing the bond angles to about
.
The greater the number of lone pairs, the lower the angle becomes.
To summarize:
- Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
- Electrons repel one another based on the VSEPR theory;
- Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.
<span>Answer: option (4) the same magnitude and the opposite sign.
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Justification:
<span /><span /><span>
</span><span>1) Electrons are negative particles thar are around the nucleus of the atom (in regions called orbitals).
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2) Protons are positive particles that are inside the nuclus of the atom.
</span><span />
<span>3) The nucleus of the atom has the same number of protons as electrons are in the orbitals of the atom.
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4) The atoms are neutral (neither positive nor negative) because there are the same number of electrons and protons and their charge are of the same magnitude but different sign: (+) + (-) = 0: positive + negative = neutral.</span>
Answer:
373.1 mL of AgCN (aq) must be poured into your electrolysis vat to ensure you have sufficient Ag to plate all of the forks.
Explanation:
Mass of silver to be precipitated on ecah spoon = 0.500 g
Number of silver spoons = 250
Total mass of silver = 250 × 0.500 g = 125 g

Moles of AgCN = n = 
Volume of AgCN solution =V
Molarity of the AgCN = 2.50 M

(1 L = 1000 mL)
373.1 mL of AgCN (aq) must be poured into your electrolysis vat to ensure you have sufficient Ag to plate all of the forks.
Answer:
<h2>
0.50 m/s</h2><h2>
</h2>
Explanation:
Velocity = distance over time
where distance = 5.20 m
time = 10.4 s.
velocity = <u> 5.20 m </u>
10.4 s.
= 0.50 m/s