Answer:
Chemical change :has change in mass, heat is needed, new element is formed, hard to reverse.......
Physicalchange:does not have change in mass, heat is not necessary, no new element is formed, easy to reverse
Answer:
315.
Explanation:
Hello.
In this case, since the given number has five significant figures as the zero is to the right of the first nonzero digit (3), if it is required to report it with three significant figures, it is necessary to "cut" it at the first five without any rounding since the subsequent zero is less than five.
Thus the number turns out:
315
Best regards.
"The solubility of gases decreases as temperature rises" statements about trends in solubility is accurate.
<u>Option: D</u>
<u>Explanation:</u>
A substance's solubility is the quantity of that component that is needed at a defined degree of temperature to produce a saturated solution in any set quantity of solvent. Some compounds like hydrochloric acid, ammonia, etc have solubility that reduces with rising temperature. They are both standard-pressure gases.
When heating a solvent with a gas absorbed in it, both the solvent and the solute spike in the kinetic energy.When the gaseous solute's kinetic energy rises, the molecules have a higher propensity to overcome the solvent molecules' connection and migrate to the gas phase. Thus, a gas's solubility reduces with rising temperature.
Answer: La Ferrassie 1
Explanation: La Ferrassie 1, often referred to as LF1, is a male Neanderthal skeleton estimated to be 70–50,000 years old. It was discovered at the La Ferrassie site in France by Louis Capitan and Denis Peyrony in 1909. The skull is the most complete Neanderthal skull ever found.
Hey there!
Na + H₂O → NaOH + H₂
First, balance O.
One on the left, one on the right. Already balanced.
Next, balance H.
Two on the left, three on the right. Let's add a coefficient of 2 in front of NaOH and a coefficient of 2 in front of H₂O, so we have 4 on each side.
Na + 2H₂O → 2NaOH + H₂
Lastly, balance Na.
One on the left, two on the right. Add a coefficient of 2 in front of Na.
2Na + 2H₂O → 2NaOH + H₂
This is our final balanced equation.
Hope this helps!
