For a proton, the charge is represented by +e
For an electron, the charge is represented by -e
The charge of an electron [e] is equal to the - 1.602 * 10^-19 Coulombs
For an ionized atom, the net charge is equal to the sum of charges in the proton and the electron in that atom.
From the question, we are told that, the iron atom has 26 protons and 7 electrons.
The net charge Q = 26 [ +e] + 7 [- e] = +19 e
+19 e = + 19 [1.602 * 10^-19 C] = + 3.04 * 10^-18 C.
Answer:
C
Explanation:
The presence of mobile electrons explains the reason why there is conduction of electricity in the solid state. Electrons are the part of atoms that are majorly responsible for the different characteristics that substances exhibit.
A good example of the conduction of electricity can be seen in the case of 2 crystalline forms of carbon. While one of the allotropes could conduct electricity, the other allotrope cannot conduct electricity.
The two allotropes we are talking about here is graphite and diamond. While graphite could be used in a whole lot of electrolysis set up as an electrode, diamond does not found use in cases like this despite its crystalline structure. The reason for this is simple.
While diamond does not contain free mobile electron in its molecule, these free mobile electrons are present in a molecule of graphite. These free mobile electrons are the main reason why graphite can conduct electricity and diamond cannot even though they are both crystalline forms of carbon.
Answer:
The change of state of wax from solid to liquid and liquid to vapors is a physical change.
Explanation:
Physical Change
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
.
These changes occur due to chemical reactions.
These may not be observed with naked eye
Example
When a candle is burned, the both physical and chemical changes occur.
The solid wax is melted into the liquid and than liquid is evaporated into vapor form. It is a physical change because just the state of mater is changed. When vapors of wax are react with oxygen in air and form carbon dioxide and ash it is a chemical change which can not be reversed.
<u>Answer:</u> The final temperature of the mixture is 51.49°C
<u>Explanation:</u>
When two samples of water are mixed, the heat released by the water at high temperature will be equal to the amount of heat absorbed by water at low temperature
The equation used to calculate heat released or absorbed follows:
![m_1\times c\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c%5Ctimes%20%28T_%7Bfinal%7D-T_1%29%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%28T_%7Bfinal%7D-T_2%29%5D)
......(1)
where,
q = heat absorbed or released
= mass of water at high temperature = 140 g (Density of water = 1.00 g/mL)
= mass of water at low temperature = 230 g
= final temperature = ?°C
= initial temperature of water at high temperature = 95.00°C
= initial temperature of water at low temperature = 25.00°C
c = specific heat of water= 4.186 J/g°C
Putting values in equation 1, we get:
![140\times 4.186\times (T_{final}-95)=-[230\times 4.186\times (T_{final}-25)]](https://tex.z-dn.net/?f=140%5Ctimes%204.186%5Ctimes%20%28T_%7Bfinal%7D-95%29%3D-%5B230%5Ctimes%204.186%5Ctimes%20%28T_%7Bfinal%7D-25%29%5D)
Hence, the final temperature of the mixture is 51.49°C
