Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
Answer:
2.15
Explanation:
For this question, we have to remember the <u>pH formula</u>:
![pH~=~-Log[H_3O^+]](https://tex.z-dn.net/?f=pH~%3D~-Log%5BH_3O%5E%2B%5D)
By definition, the pH value is calculated when we do the -Log of the concentration of the <u>hydronium ions</u> (
). So, the next step is the calculation of the <u>concentration</u> of the hydronium ions. For this, we have to use the <u>molarity formula</u>:

We already know the number of moles (0.0231 moles) and the volume (3.33 L). So, we can plug the values into the molarity formula:

With this value, now we can calculate the pH value:
![pH~=~-Log[0.00693~M]~=~2.15](https://tex.z-dn.net/?f=pH~%3D~-Log%5B0.00693~M%5D~%3D~2.15)
<u>The pH would be 2.15</u>
I hope it helps!
An anchoring phenomenon anchors all of the learning within a unit. So, it is a unit level event that the classroom is trying to make sense of as they engage in a series of lessons.
Since the questions the students ask about the anchor drive the learning within the unit, the anchor should be complex and require an understanding of several big science ideas to explain.
At strategic moments, the class revisits the anchoring phenomenon to review their initial questions to see which they have answered, which they are making progress on, and what new questions they may have to help us continue learning about the phenomenon.
Throughout the unit, the classroom and each student should be given opportunities to share their thinking and how it relates to the anchoring phenomenon.
YOU SHOULD PUT IT IN YOUR OWN WORDS THOUGH <3