Answers:
A) 2040 kg/m³; B) 58 600 km
Explanation:
A) Density


<em>B) Radius</em>



![r= \sqrt [3]{ \frac{3V }{4 \pi } }](https://tex.z-dn.net/?f=r%3D%20%5Csqrt%20%5B3%5D%7B%20%5Cfrac%7B3V%20%7D%7B4%20%5Cpi%20%7D%20%7D)
![r= \sqrt [3]{ \frac{3\times 8.268 \times 10^{23} \text{ m}^{3}}{4 \pi } }= \sqrt [3]{ 1.974 \times 10^{23} \text{ m}^{3}}= 5.82 \times 10^{7} \text{ m}=\text{58 200 km}](https://tex.z-dn.net/?f=r%3D%20%5Csqrt%20%5B3%5D%7B%20%5Cfrac%7B3%5Ctimes%208.268%20%5Ctimes%2010%5E%7B23%7D%20%5Ctext%7B%20m%7D%5E%7B3%7D%7D%7B4%20%5Cpi%20%7D%20%7D%3D%20%5Csqrt%20%5B3%5D%7B%201.974%20%5Ctimes%2010%5E%7B23%7D%20%5Ctext%7B%20m%7D%5E%7B3%7D%7D%3D%205.82%20%5Ctimes%2010%5E%7B7%7D%20%5Ctext%7B%20m%7D%3D%5Ctext%7B58%20200%20km%7D)
Atomic mass Cu = 63.546 a.m.u
63.546 g ---------------- 6.02x10²³ atoms
22 g --------------------- ??
22 x (6.02x10²³ ) / 63.546 => 2.08x10²³ atoms
hope this helps!
Answer:
20cm^2
Explanation:
Here, Density= Mass/ Volume
=100/5
= 20 cm^2
Answer:
Chemical reactions do not involve changes in the chemical bonds that join
atoms in compounds :
<u>False</u>
Explanation:
Chemical reaction are the reaction in which old bonds break and new bonds are formed . The formation of new bond result in formation of new compounds . This happen because new bond are result of linking different atoms by the bond.
For example : Water formation from Oxygen and Hydrogen is a chemical process :

Original(old) bonds are :
H-H bond in H2 and O-O bonds in O2
In H2 = Hydrogen is joined to Hydrogen
IN O2 = Oxygen is joined to oxygen
New Bonds =
O-H bonds in water (H2O)
Oxygen is joined to hydrogen = New Bond formation
Hence,
<u>Chemical reactions do involve changes in the chemical bonds that join
</u>
<u>atoms in compounds</u>
<u />
Answer:
1. Exothermic.
2. -1598 kJ.
Explanation:
Hello!
1. In this case, according to the reaction, we can infer that 799 kJ of energy are evolved (given off, released) it means that the enthalpy of reaction is negative as the reactants have more energy than the products; which means this is an exothermic reaction.
2. Here, as we know that the enthalpy of reaction is -799 kJ/mol, we can compute the q-value as shown below, considering the reacted 2 moles of solid iron:

Which means that 1598 kJ of energy are evolved when 2 moles of solid iron react.
Best regards!