Answer:
9 (1-2x²)
Explanation:
The given expression is:
30 - 9x²*2 - 21 - 4 + 4
The first step is to compute the multiplication. This will give:
30 - 18x² - 21 - 4 + 4
Then, we will add like terms as follows:
(30-21-4+4) - 18x²
= 9 - 18x²
Finally, we can take the 9 as a common factor from both terms, this will give:
9 (1-2x²)
Hope this helps :)
Answer:
True
Explanation:
It's true because the pH is a measure of how basic or acid a solution is. In an acidic medium, the pH scales goes from 0 to 7. While in a basic medium goes from 7 to 14. The lower the pH value of the most acid the solution is.
1. The expression pH = -log(molar concentration of hydronium) allow to calculate the pH of a solution.
2. On the other hand, the expression pOH = -log(molar concentration of hydroxide) allow to determine the pOH of a solution.
The values of pH and pOH always obey the following expression:
pH + pOH = 14
Thus if for instance the pH becomes smaller the pOH must become bigger in order to fulfill the equation. Which means that the concentration of hydronium ions is greater than the hydroxide concentration.
For example, in an acidic medium:
if pH= 3, pOH= 11
In this case the molar concentration of hydronium is 0,001M. And the molar concentration of hydroxide ions is just 0,00000000001M.
Answer:
no
Explanation:
Because I have lost and I dont know where is the worksheet
There are things called "Reactants" and "Products" All chemical equations look something like "A + B →C (+ D...)," in which each letter variable is an element or a molecule (a collection of atoms held together by chemical bonds). The arrow represents the reaction or change taking place. Some equations may have a double-headed arrow (↔), which indicates that the reaction can proceed either forward or backward. When a compound has been written out, you must identify the elements and know their chemical symbols. The first element written is “first name” of the compound. Use the periodic table to find the chemical symbol for the element. So here is an example: Dinitrogen hexafluoride. The first element is nitrogen and the chemical symbol for nitrogen is N. To know the numbers of atoms that are present for each element you can just look at the prefix from the element For example: Dinitrogen has a the prefix “di-“ which means 2; therefore, there are 2 atoms of nitrogen present.
Write dinitrogen as N2.
Now for the second element or "last name" of the compound whatever will follow the first element so like; Dinitrogen hexafluoride. The second element is fluorine. Simply replace the “ide” ending with the actual element name. The chemical symbol for fluorine is F.
But the more you practice with, the easier it will be to decipher chemical formulas in the future and learn the language of chemistry.
Sulfur dioxide: SO2
Carbon tetrabromide: CBr4
Diphosphorus pentoxide: P2O5 ← That is one of the examples I'll give you.
have a gooooood daaaaayy
<span>The superscripts in an electron configuration represents the number of electrons and protons in an element. </span>
