If the value of H is positive, it means you have to add that much heat to complete the reaction. If H is negative, it means that much heat is released during the chemical process. Because it is -73 kJ, 73 kJ of heat are released in the reaction.
Answer:
The atom resembles plum pudding
Explanation:
The discovery of the electron in 1897 by J. J Thomson and the proton in 1917 by Rutherford most directly refuted or replace the idea that the atom resembles plum pudding.
Explanation:
Both conduction and convection are both forms of heat transfer from one place to another.
- In conduction, there must be contact between two bodies for the process to take place but in convection, the matter moves to transfer heat.
- Conduction mostly occurs in solid substances whereas convection occurs mostly in fluids.
- Heat transfer in conduction is quite slow compared to convection which is much faster.
Example of conduction is heating of iron pot when cooking
Example of convection is the refrigerating system.
<u>Answer:</u> The electronic configuration of gallium is written below and number of valence electrons is 3.
<u>Explanation:</u>
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
Valence electrons are defined as the electrons present in the outermost shell of an atom.
We are given:
An element Gallium having atomic number as 31.
Number of electrons = 31
Electronic configuration of Gallium is: 
This element has 3 electrons in its outermost shell. So, the number of valence electrons is 3
Hence, the electronic configuration of gallium is written below and number of valence electrons is 3.
Ice is a mixture and it can be a compound at the same time. A mixture is when you have to substance's put together fro example you can mix salt and sugar together. But a compound is when two different elements or molecules are combined. Ice cream is a mixture or cream and sugar mainly.
