They each have the same number of protons. A potassium atom (atomic number 19) and a bromine atom (atomic number 35) can form a chemical bond through a transfer of one electron. The potassium ion that forms has 18 electrons.

Transcribed image text: When potassium reacts with bromine to form an ionic compound, each metal atom loses electron(s) and each nonmetal atom gains electron(s). There must be potassium atom(s) for every bromine atom(s) in the reaction.

Explanation: As an halogen, bromine is a potent oxidant.

The nucleus of an atom of potassium contains 19 protons and 20 neutrons.

Potassium atoms have 19 electrons and 19 protons with one valence electron in the outer shell. Potassium is considered chemically similar to sodium, the alkali metal above it on the periodic table. Under standard conditions potassium is a soft silvery-white metal.

In Cu atom (3d104s1) the 3d10 1s completely filled but in its Cu2+ ion (3d94s0) one of the 3d-orbitals is only half filled. Therefore, copper is a transition elements. Therefore, zinc is not considered as a true transition element, but its electronic configuration does not fit in the quantum mechanical definition.

Although copper has 3d10 configuration,it can lose one electron from this arrangement. Hence,Cu+2 has 3d9 configuration.So according to the definition that transition metal cations have partially filled (n-1)d subshell,copper can be regarded as a transition metal.

The zinc ion has completely filled d orbitals and also it does not meet the definition either. Therefore, zinc is not a transition element.

Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams. This is because Cu is one of the oxidation states viz. +2 has incompletely filled 3d subshell (3d9) while Zn has completely filled3d10 only.

The 4s electrons are lost first followed by one of the 3d electrons. The electrons lost first will come from the highest energy level, furthest from the influence of the nucleus. So the 4s orbital must have a higher energy than the 3d orbitals.

Electrons usually enter the 4s orbital before the 3d because the 4s is initially lower in energy. However, from Scandium and onwards, the 3d orbital of transition metals actually becomes lower in energy than the 4s, which is why we write 3d before 4s in the configuration.

Why does Ti5+ not exist? a. Because titanium only has 4 valence electrons you would have to add a core electron to create aTi5+ ion. Because titanium only has 4 valence electrons you would have to remove a core electron to create a Ti5+ ion.

As you can see, the 4S orbital is filled BEFORE the 3D orbital as it has a lower energy, and therefore 3D has to be placed in the 4th row in the periodic table, after 4S. This trend continues as you go down the rows.

So because the 4s orbitals has the lower energy, it gets filled first. When 3d orbitals are filled, 4s is no longer lower in energy. Hence electrons are lost from 4s orbital first, because electrons lost first will come from the highest energy level (furthest away from the nucleus).

The shape of the 4s orbital. That on the left is sliced in half to show the two spherical nodes of the 4s orbital. The shape on the right shows the nodal structure of the 4s-orbital. While still spherical, the higher s-orbitals (5s, 6s, and 7s) are more complex since they have more spherical nodes.

The p orbital is a dumbbell shape because the electron is pushed out twice during the rotation to the 3p subshell when an opposite-spin proton aligns gluons with two same-spin protons.