An element is a species of atom that has the same amounts of electrons and protons in their nuclei. To know which of these substances are elements, we can look it up in the periodic table of elements. The elements are as follows:
1.silicon
2.lead
3.silicone
5.iodine
Answer is c , because it's convection currents
pH is referred to as the scale to describe the hydronium ion concentration of a
solution. It is used to measure the acidity or basicity of a solution. pH of an acidic solution is less than 7, a neutral solution is 7, and a basic solution is greater than 7.
pH can be calculated using the formula:
![pH = - log [H_{3}O^{+}]](https://tex.z-dn.net/?f=%20pH%20%3D%20-%20log%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%20%20)
Given the pH of solution is 3.2.
Finding out the concentration of hydronium ion from pH.
![pH = - log[H_{3}O^{+}]](https://tex.z-dn.net/?f=%20pH%20%3D%20-%20log%5BH_%7B3%7DO%5E%7B%2B%7D%5D)
![3.2 = - log [H_{3}O^{+}]](https://tex.z-dn.net/?f=%203.2%20%3D%20-%20log%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%20%20)
![[H_{3}O^{+}] = 10^{-3.2}](https://tex.z-dn.net/?f=%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3D%2010%5E%7B-3.2%7D%20%20%20%20)
![[H_{3}O^{+}] = 6.3 * 10^{-4} M](https://tex.z-dn.net/?f=%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3D%20%20%206.3%20%2A%2010%5E%7B-4%7D%20M%20%20)
Therefore, the hydronium ion concetration of the solution is 
The independent variable is the variable being changed. In this case, the independent variable is the calculators. The dependent variable is essentially what you are looking for that <u>depends</u> on the independent variable. In this case it would be time. The constant variable or controlled variable are something that doesn't change and would skew the results. One may be the exact same problem for both groups. Try to come up with two more.
Answer:
I think the answer is Toledo
