The pH of pure water is neutral because the concentration of hydronium ions equals that of hydroxide ions.
Answer: Option A
<u>Explanation:</u>
Water is one of the most important constituents of living being. It is said that there is no life without water. So that water need to neutral in nature to save life. Pure water is composed of hydronium 
and hydroxide 
ions. It is known that hydronium ions are acidic in nature with concentration of 
.
Similarly, the hydroxide ions which are basic in nature will be in same concentration as that of hydronium ions. So, as the concentration of basic and acidic elements are equal with the same strength of pH, the combination of these ions lead to formation of pure water with the pH being neutral.
It would be a physical change. It’s still water just in a different physical form. If it was a chemical change, it would no longer be water. For example, when the ice melts back into water...it’s still water.
Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life is represented by 
= rate constant
Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.
As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.
Whichever one has the smallest amount of H+ Ions.
Answer:
To obtain a more accurate read on temperature, the researcher should make sure to measure temperature by Celsius degrees rather than Fahrenheit.
Explanation:
Temperature is a measure of heat intensity. In food science experiments, you should always require an exact description of heat intensity. The most commonly used unit of temperature in the laboratory is the Celsius degree because the Celsius temperature scale is based on the boiling and freezing points of pure water. The difference between the points of boiling and freezing temperatures (at 1 atmosphere of air pressure) is divided into 100 equal units, making a Celsius degree 0.01 of the difference between the boiling and freezing points of water, making it the most accurate method of exact temperature reading. It is important to use the Celsius scale if you have a thermometer that reads Celsius and Fahrenheit.
