If 1mole ------------- is ---------------- 6.02*10²³
than 0.25mole ----- is ---------------- x
x = [0.25mole*6.02*10²³]/1mole = <u>1,505*10²³</u>
Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out possible to set up the following energy equation for both objects 1 and 2:

In terms of mass, specific heat and temperature change is:

Now, solve for the final temperature, as follows:

Then, plug in the masses, specific heat and temperatures to obtain:

Yet, the values do not seem to have been given correctly in the problem, so it'll be convenient for you to recheck them.
Regards!
Answer:
Most stars are rather simple things. They come in a variety of sizes and temperatures, but the great majority can be characterized by just two parameters: their mass and their age. (Chemical composition also has some effect, but not enough to change the overall picture of what we will be discussing here. All stars are about three-quarters hydrogen and one-quarter helium when they are born.)
Answer: The ionization of pure water forms <u><em>hydroxide and hydronium ions.</em></u>
Explanation:
Ionization is a reaction in the pure water in which water breaks down into its constituting ions that hydronium ion and hydroxide ions.

One molecule of water looses its proton to form hydroxide ion and l=the lost protons get associated with another water molecule to form hydronium ion.