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.
Answer:
Mass of 205 mL of the liquid is 164 g
Explanation:
We know, 
Here density of liquid is 0.798 g/mL and volume of liquid is 205 mL
So, mass of liquid = 
= 
= 164 g
hence mass of 205 mL of the liquid is 164 g.
Answer:
B) 0.32 %
Explanation:
Given that:
Concentration = 1.8 M
Considering the ICE table for the dissociation of acid as:-
The expression for dissociation constant of acid is:
![K_{a}=\frac {\left [ H^{+} \right ]\left [ {CH_3COO}^- \right ]}{[CH_3COOH]}](https://tex.z-dn.net/?f=K_%7Ba%7D%3D%5Cfrac%20%7B%5Cleft%20%5B%20H%5E%7B%2B%7D%20%5Cright%20%5D%5Cleft%20%5B%20%7BCH_3COO%7D%5E-%20%5Cright%20%5D%7D%7B%5BCH_3COOH%5D%7D)
Solving for x, we get:
<u>x = 0.00568 M</u>
Percentage ionization = 
<u>Option B is correct.</u>
Answer:
Option B. Cation that is smaller than the original atom.
Explanation:
Magnesium is a divalent element. This implies that magnesium can give up 2 electrons to become an ion (cation) as shown below:
Mg —> Mg²⁺ + 2e¯
Next, we shall write the electronic configuration of magnesium atom (Mg) and magnesium ion (Mg²⁺). This can be written as follow:
Mg (12) = 2, 8, 2
Mg²⁺ (10) = 2, 8
From the above illustration, we can see that the magnesium atom (Mg) has 3 shells while the magnesium ion (Mg²⁺) has 2 shells.
This simply means that the magnesium ion (Mg²⁺) i.e cation is smaller that the original magnesium atom (Mg).
