Answer:
As a substance melts, and goes from a solid to a liquid state, the kinetic energy of the molecules increases, and the molecules move faster, and they separate further and further away from each other. The intermolecluar forces holding the molecules together become weaker. This is why a liquid can take fill the shape of its container, whereas a solid has a fixed shape.
Explanation:
take your notes man
Hi There!
Question - What are cells at express the same gene?
Answer - A. the same
Why - Every single cell in a person body has the exact same DNA.
Hope This Helps :)
Answer:
pH = 6.999
The solution is acidic.
Explanation:
HBr is a strong acid, a very strong one.
In water, this acid is totally dissociated.
HBr + H₂O → H₃O⁺ + Br⁻
We can think pH, as - log 7.75×10⁻¹² but this is 11.1
acid pH can't never be higher than 7.
We apply the charge balance:
[H⁺] = [Br⁻] + [OH⁻]
All the protons come from the bromide and the OH⁻ that come from water.
We can also think [OH⁻] = Kw / [H⁺] so:
[H⁺] = [Br⁻] + Kw / [H⁺]
Now, our unknown is [H⁺]
[H⁺] = 7.75×10⁻¹² + 1×10⁻¹⁴ / [H⁺]
[H⁺] = (7.75×10⁻¹² [H⁺] + 1×10⁻¹⁴) / [H⁺]
This is quadratic equation: [H⁺]² - 7.75×10⁻¹² [H⁺] - 1×10⁻¹⁴
a = 1 ; b = - 7.75×10⁻¹² ; c = -1×10⁻¹⁴
(-b +- √(b² - 4ac) / (2a)
[H⁺] = 1.000038751×10⁻⁷
- log [H⁺] = pH → 6.999
A very strong acid as HBr, in this case, it is so diluted that its pH is almost neutral.
Answer:
SAMPLE A - pure substance.
SAMPLE B - homogeneous mixture.
SAMPLE C - heterogeneous mixture.
Explanation:
Answer:
The energy levels in an atom are similar to the rungs of a ladder, but they get closer together as they get farther from the nucleus. For an electron to move from one energy level to the next higher level, it must gain the right amount of energy. If less than that amount is available, the electron stays where it is.
Explanation:
Hope this helped! Goodluck on your test or whatever you're doing! Stay safe ♥♥♥
