16318616165161616156165161961616
Answer: The element shown in the image is Helium (He).
Explanation: We are given a image of an atom having protons, neutrons and electrons.
Number of protons as shown in image = 2
Number of neutrons as shown in image = 2
Number of electron as shown in image = 2
Atomic number = Number of protons = Number of electrons
Atomic number of the element = 2
Atomic Mass = Number of protons + Number of neutrons
Atomic mass = 2 + 2 = 4
The element having Atomic number = 2 and mass number = 4 is Helium.
Element = 
Answer:
Initially 
of nitrogen dioxide were in the container .
Explanation:
Volume of the container at low pressure and at room temperature =
Number of moles in the container = 
After more addition of nitrogen gas at the same pressure and temperature.
Volume of the container after addition = 
Number of moles in the container after addition=
Applying Avogadro's law:
(at constant pressure and temperature)
Initially of nitrogen dioxide were in the container .
Given what we know, we can confirm that as with any experiment, the control variable will be the one that through each trial of the experiment, no matter how many times it is performed, stays constant.
<h3>What is a controlled variable?</h3>
- A variable that remains constant through an experiment.
- They are used to compare results to the normal condition.
- They are also used to isolate the changes to one factor at a time and thus know its exact effects on the outcome.
- This increases the accuracy of the data and the subsequent conclusion.
Therefore, we can confirm that if a variable stays constant through each phase and trial of an experiment, it is considered to be a controlled variable and is useful in order to increase the accuracy of the conclusion.
To learn more about control variables visit:
brainly.com/question/17555102?referrer=searchResults
Answer:
0.46 grams (C₆H₅)₂CO
Explanation:
To find the mass of benzophenone ((C₆H₅)₂CO), you need to (1) convert mmoles to moles and then (2) convert moles to grams (via molar mass). It is important to arrange the conversions/ratios in a way that allows for the cancellation of units. The final answer should have 2 sig figs to match the sig figs of the given value (2.5 mmoles).
Molar Mass ((C₆H₅)₂CO): 13(12.011 g/mol) + 10(1.008 g/mol) + 15.998 g/mol
Molar Mass ((C₆H₅)₂CO): 182.221 g/mol
2.5 mmoles (C₆H₅)₂CO 1 mole 182.221 g
----------------------------------- x ------------------------ x ------------------- =
1,000 mmoles 1 mole
= 0.46 grams (C₆H₅)₂CO
