Question

Name the element: 1s2 252 2p 3s2 3p6 453 3d9

O Strontium Sr
O Krypton Kr
O Tungsten W
O Copper Cu
Silver Ag
Silicon Si

Answer 1

Cu

Step-by-step explanation:

The sublevel notation is

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁹

The element is unknown;

To find the element, sum the superscipts because the indicate the electrons;

2 + 2 + 6 + 2 + 6 + 2 + 9 = 29

The element with 29 electrons is copper