QUICK ANSWER
The name of the covalent compound N2O5 is dinitrogen pentoxide, more commonly known as nitrogen pentoxide. This covalent compound is part of a bigger group of compounds, nitrogen oxides, created purely from nitrogen and oxygen
Answer: 1.67 kg
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed=
=
(1kJ=1000J)
m= mass of substance = ?
c = specific heat capacity = 
Change in temperature ,
Putting in the values, we get:

(1kg=1000g)
Thus the mass (in kg) of the copper sample is 1.67
The first answer is -.595454 the second answer is -1.9488
Answer:
Yes. Example: <u>Sulfur hexafluoride (SF₆) molecule</u>
Explanation:
According to the octet rule, elements tend to form chemical bonds in order to have <u>8 electrons in their valence shell</u> and gain the stable s²p⁶ electronic configuration.
However, this rule is generally followed by main group elements only.
Exception: <u>SF₆ molecule</u>
In this molecule, six fluorine atoms are attached to the central sulfur atom by single covalent bonds.
<u>Each fluorine atom has 8 electrons in their valence shells</u>. Thus, it <u>follows the octet rule.</u>
Whereas, there are <u>12 electrons around the central sulfur atom</u> in the SF₆ molecule. Therefore, <u>sulfur does not follow the octet rule.</u>
<u>Therefore, the SF₆ molecule is known as a </u><u>hypervalent molecule</u><u> or expanded-valence molecule.</u>