<span>The maximum number of electrons that can be contained in an energy level (also called shells) is determined by the formula 2n^2, where n is the energy level; So, when n = 1, the maximum number of electrons is 2; when n = 2, the maximum number of electrons is 2*(2^2) = 8; when n = 3, the maximum number of electrons is 2 * (3^2) = 18; and when n=4, the maximum number of electrons is 2(4^2) = 32. So, briefly the series is 2, 8, 16, 32.</span>
Answer:
Explanation:
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
Example: Water decomposes into a mixture of hydrogen and oxygen when an electric current is passed through the liquid. Hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances - elements.
Each element is represented by a unique symbol. The notation for each element can be found on the periodic table of elements.
The elements can be divided into three categories that have characteristic properties: metals, nonmetals, and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.
Environment, Temperature, and Food.
Answer:
last one
they can contain mercury that is Very harmful to humans
A 0.25m solution of NaCl is defined as a solution consisting of 0.25mol NaCl dissolved in 1kg water:
Which choice fits this definition: None does. I suggest that you recheck the data you have submitted - you have a mixture of moles, mass, etc and it is easy to make a mistake.
d) looks promising if it was: 1.0 mol NaCl dissolved in 4kg water.
I have overlooked C) as possible 0.25mol NaCl in 1kg water as being a little too obvious.
