(in the image) What Is the noble gas configuration for strontium (atomic number = 38)? Given: He (atomic number = 2) Ne (atomic number = 10) Ar (atomic number = 18) Kr (atomic number = 36) B В A [Kr 45Kr 5​

[Kr] 5s²

Explanation:

From the question given above, the following data were obtained:

Atomic number of strontium (Sr) = 38

Electronic configuration =?

Next, we shall determine the electronic configuration of the noble gas element before strontium (Sr).

The noble gas element before strontium (Sr) is krypton (Kr). Thus, the electronic configuration of krypton (Kr) is given below:

Kr (36) => 1s² 2s²2p⁶ 3s²3p⁶ 3d¹⁰ 4s²4p⁶

Finally, we shall determine the electronic configuration of strontium (Sr). This can be obtained as follow:

Kr (36) => 1s² 2s²2p⁶ 3s²3p⁶ 3d¹⁰ 4s²4p⁶

Sr (38) =>?

Sr (38) => 1s² 2s²2p⁶ 3s²3p⁶ 3d¹⁰ 4s²4p⁶ 5s²

But

Kr (36) => 1s² 2s²2p⁶ 3s²3p⁶ 3d¹⁰ 4s²4p⁶

Therefore,

Sr (38) => [Kr] 5s²

that's what i got you can count the number of atoms