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:
Physical change
Explanation:
Chemical change is defined as the process in which new substance with different properties is formed from old substance and the process is irreversible while physical change is a reversible process and changes only physical properties of a substance.
<em>The given experiment is an example of physical change because it is just the physical act of dissolving. The metal disk is dissolving in sodium acetate and the process is exothermic and the process is reversible as well.</em>
Hence, the correct answer is "physical change".
When you cook food like eggs, this is a chemical change. Agree.
The runny egg turns into a solid. One type of matter must be changing into another type
When you cook food like potatoes, this is a chemical change. Agree.
Boiling potatoes causes changes in the structure of the starch. Higher heat as in baking, roasting, or frying causes the development of a harder crust on the potato. This suggests that chemical changes have taken place.
When a candle burns, the wick of the candle and wax turn into nothing. Disagree.
The <em>Law of Conservation of Mass</em> says that <em>you can’t turn matter into nothing</em>. What must be happening is that the wick and the wax are changing into other substances that we can’t see, such as colourless gases of carbon dioxide and water vapour.
