Answer: Atomic Nucleus!
Explanation: All atoms have a dense central core called the atomic nucleus. Forming the nucleus are two kinds of particles: protons, which have a positive electrical charge, and neutrons, which have no charge.
(Yes, it was from google.)
Answer:
0.11mole
Explanation:
Let us assume that the condition is at standard temperature and pressure(STP);
Given parameters:
Volume of water = 2.45L
Unknown:
Number of moles found in this volume of water = ?
Solution;
At STP;
Number of moles = 
Input the parameters and solve;
Number of moles of water = 
= 0.11mole
The number of moles of water found is 0.11mole
The new volume of the air bubble that has an initial volume of 5.0 ml released at the bottom of a lake where the pressure is 3.0 atm is 15mL.
<h3>How to calculate volume?</h3>
The volume of a given gas can be calculated by using the following formula:
P1V1 = P2V2
Where;
- P1 = initial pressure
- V1 = initial volume
- P2 = final pressure
- V2 = final volume
5 × 3 = 1 × V2
15 = V2
V2 = 15mL
Therefore, the new volume of the air bubble that has an initial volume of 5.0 ml released at the bottom of a lake where the pressure is 3.0 atm is 15mL.
Learn more about volume at: brainly.com/question/1578538
Therefore option c , i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observations.
<h3>What is the reaction between Magnesium and Hydrogen ?</h3>
Magnesium reacts with hydrochloric acid to produce hydrogen gas
Mg (s) + 2 HCl (aq) → MgCl₂ (aq) + H₂ (g)
In this reaction, the magnesium and acid are gradually used up , which can be seen in the test tube 2 .
A chemical reaction is taking place in Test tube 2 ,
Hydrogen gas is released in test tube 2 ,
Energy is released in the reaction involving hydrochloric acid and we can see in test tube 2 the reaction is going on
therefore option C i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observation.
To know more about the chemical reaction between Magnesium and Hydrogen and this test.
brainly.com/question/19062002
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They are able to be divided by a chemical reaction
