Answer:
20
Explanation:
Hi there!
We need to find the atomic number of an atom that has 20 protons and 20 neutrons
the atomic number of an atom is equivalent to the amount of protons an atom has, as the number of protons determines what element an atom is.
Since the atom has 20 protons, the atomic number of the said atom is <u>20</u>
Hope this helps!
Answer:
A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.
Explanation:
Hello.
In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:

As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.
Best regards.
Answer:
x=30
Explanation:
I will try to explain with a drawing.
This is a rule of three.
If you are wondering what the rule of three is. It's when u have 3 informations and you solve.
Answer:
The suns mass effects the solar system by having a great gravitational pull. This cause the success rate to grow lower each time.
What is the difference between the two numbers? That is your answer