Answer:An oxygen atom usually has 8 protons, 8 neutrons, and 8 electrons. Looking at the periodic table, oxygen has atomic number 8 and atomic weight 15.999.
Explanation:
Answer:
There are 6.022x10^23 molecules
Answer:
Its in the Explanation
Explanation:
Here's what I got.
Aluminium-27 is an isotope of aluminium characterized by the fact that is has a mass number equal to
27
.
Now, an atom's mass number tells you the total number of protons and of neutrons that atom has in its nucleus. Since you're dealing with an isotope of aluminum, it follows that this atom must have the exact same number of protons in its nucleus.
The number of protons an atom has in its nucleus is given by the atomic number. A quick looks in the periodic table will show that aluminum has an atomic number equal to
13
.
This means that any atom that is an isotope of aluminum will have
13
protons in its nucleus.
Since you're dealing with a neutral atom, the number of electrons that surround the nucleus must be equal to the number of protons found in the nucleus.
Therefore, the aluminium-27 isotope will have
13
electrons surrounding its nucleus.
Finally, use the known mass number to determine how many neutrons you have
mass number
=
no. of protons
+
no. of neutrons
no. of neutrons
=
27
−
13
=
14
Your welcome :)
Answer:
The number of moles = 0.06 moles
Explanation:
i) Formula
Number of moles = Mass of the sample ÷ Molar masses of the substances
ii) Number of moles = 10.0 ÷ (137)+(19×2)
= 10.0 ÷ 175
= 0.06 moles
Answer: Boiling and Evaporation: Evaporation is the change of a substance from a liquid to a gas. Boiling is the change of a liquid to a vapor, or gas, throughout the liquid.
Explanation: Boiling and Evaporation: Evaporation is the change of a substance from a liquid to a gas. Boiling is the change of a liquid to a vapor, or gas, throughout the liquid.
