Answer:- b. +3
Explanations:- Charge of a metal ion is equal to the number of valence electrons it has as it loses these electrons to have its nearest noble gas like electron configuration.
Al has 3 valence electrons and being a metal it loses all of these and so the charge of Al ion is +3. It could be shown as:

So, the right choice is b. 3+.
Answer:
550 m/s
Explanation:
The average molecular speed (v) is the speed associated with a group of molecules on average. We can calculate it using the following expression.

where,
We can use the info of argon to calculate the temperature for both samples.

Now, we can use the same expression to find the average molecular speed in a sample of Ne gas.

Parasite lives off the host so if the host dies, they are forced to look for another host. They can also leave its host if the parasite kills its host when it finds a new host, because if the parasite does not have a host its dies off.
Hope this can help explain
Answer:
Explanation:
To slow down this reaction, we can use any of the methods listed below:
- Increase the size of the magnesium by using solid lumps of the metal. This will take a much faster time to react than powered and granulated magnesium.
- Reduce the concentration of the acid.
- Let the reaction take place at a much lower temperature than that given.
These conditions will slow down a chemical reaction.
Answer:
The mole is the SI unit for amount of a substance.
Explanation:
Just like the dozen and the gross, it is a name that stands for a number. There are therefore 6.02 × 10 23 water molecules in a mole of water molecules.