Answer:
3,4
Explanation:
Hydrogen has no other electron hence there is no screening of the valence electron by inner electrons. It is the lightest known element with a relative molecular mass of 2. Screening effect refers to the fact that inner or core electrons prevent the outermost electron from feeling the attractive force of the nucleus.
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Answer: Protons
The atom in a sample of an element must contain nuclei with the same number of protons. If the protons change in number, then the element will modify as well.
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Answer:
I think
1. A
2. 400
3. 100
4. IDK srry
Explanation:
Ijust want to help, but I also want brainliest
The claim is that NaCl mixture is a homogeneous mixture.
Homogeneous mixture means that the components of the mixtures cannot be determined or separated by the naked eye. However, these components can be separated using physical means, such as boiling, evaporation and condensation which will be used in this experiment.
First, we need to prepare one molar solution of NaCl. To do so, we will dilute a mass of 58.44 grams (molar mass of NaCl) in 1 liter of water.
By this, we will have NaCl solution.
We can notice that once the NaCl is diluted in water, all what you can see is a clear solution. You cannot see the separate particles of NaCl in water.
..............> observation I
Now, we will heat this solution until it boils and water starts evaporating. We will place a cold surface above the steam coming out from the boiling solution.
What we will observe is that when all the water evaporates, we can see white precipitate of NaCl in the bottom of the container. Examining the cold surface placed above the steam, we can see that the water has condensed on this surface.
.........>observation II
Based on this, we managed to use boiling, evaporation and condensation (physical methods) to restore the components of the solution separately.
.............>conclusion
Based on observation I, observation II and the conclusion. we were able to prove that NaCl solution is a homogeneous mixture.
Answer:
The amount is 
Explanation:
From the question we are told that
The distance traveled per day is 
The cost of one liter is 
The car's gas mileage is 
Generally the amount of distance covered in one week is evaluated as
The amount of gas used in one week by the car is mathematically represented as
=> 
=> 
converting to liters
Thus the amount spent on gas in one week is
=> 
=>
