Which value changes when a Cu atom becomes a Cu2+ ion? 1.
mass number
2.
oxidation number
3
number of protons
4.
number of neutrons

2. Oxidation number

Explanation:

In an atom, M, nuclide notation is expressed as:

ₓᵃMⁿ

Where a is mass number (Protons + neutrons)

x is atomic number (Protons)

And n is the charge of the atom (Protons - Electrons ; Oxidation number)

The atom Cu²⁺ has lost 2 electrons, changing, thus, its oxidation number.

Right answer is:

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.