Aluminium has a relative atomic mass of 27 and atomic number 13. How many electrons does it have?401427132What is the maximum number of electrons that can fit into the third shell around an atom’s nucleus?8161023A magnesium atom has 12 electrons. How many electrons does it have in its outer shell?841024A chlorine atom has 17 electrons. Its electronic structure in numbers is:2, 4, 8, 32, 7, 82, 8, 74, 8, 55Referring to the periodic table, which element has the electronic structure 2, 8, 4?AluminiumPhosphorousSiliconSulfur6Which of the following elements has a full outer shell of electrons?OxygenFluorineNeonNitrogen

It seems like you've asked multiple questions in one go. Let's break them down:

1. Aluminium has a relative atomic mass of 27 and atomic number 13. How many electrons does it have?

   • Answer: Aluminium has 13 electrons. The atomic number of an element is equal to the number of protons in its nucleus, and in a neutral atom, the number of protons is equal to the number of electrons.

2. What is the maximum number of electrons that can fit into the third shell around an atom’s nucleus?

   • Answer: The third shell can hold a maximum of 8 electrons.

3. A magnesium atom has 12 electrons. How many electrons does it have in its outer shell?

   • Answer: Magnesium has 2 electrons in its outer shell. The electron configuration of magnesium is 2, 8, 2.

4. A chlorine atom has 17 electrons. Its electronic structure in numbers is:

   • Answer: The electronic structure of chlorine is 2, 8, 7.

5. Referring to the periodic table, which element has the electronic structure 2, 8, 4?

   • Answer: The element with the electronic structure 2, 8, 4 is Silicon.

6. Which of the following elements has a full outer shell of electrons?

   • Answer: Neon has a full outer shell of electrons.