B - Atomic number. Dmitri Mendeleev organised the table according to atomic weight, however this caused problems with elements such as iodine and tellurium, Iodine has a higher mass, but a lower atomic number. And to make iodine in the same group as similar elements (halogens), Mendeleev had to break his own rules and put it before tellurium in the table. Moseley fixed this problem by ordering the elements according to atomic (proton) number.

3 0

3 years ago

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Cu2O + 2 HCl → 2 CuCl + H2O

ivann1987 [24]

What is your question please write properly>-< >_

8 0

2 years ago

Consider the resonance structures of formate. the first lewis structure of formate has a central carbon atom. a hydrogen atom an

OleMash [197]

So,

Formate has a resonating double bond.

In molecular orbital theory, the resonating electrons are actually delocalized and are shared between the two oxygens. So the carbon-oxygen bonds can be described as 1.5-bonds (option B). I'm not sure if option C is correct, however, because the likelihood of both delocalized electrons being in the area of one oxygen atom is less than 50%.<span />

6 0

3 years ago

Which of the following symbols represents a chlorine ion with a stable arrangement of eight valence electrons?

frozen [14]

A stable arrangement of eight valence electrons : ³⁵Cl⁻¹

<h3>Further explanation</h3>

Chlorine is a halogen gas, located in group 17, p block

Chlorine has an atomic number of 17 and an atomic mass of 35

Electron configuration: [Ne] 3s²3p⁵

If we look at the electron configuration, then Cl will bind 1 more electron so that the configuration is stable like Argon (atomic number 18)

So by binding this one electron, chlorine forms negative ions (anions)

³⁵Cl⁻¹

B. Cl⁻² binds 2 electrons, exceeding the octet rule

C. Cl⁺¹, releases 1 electron, remains unstable

D. Cl, the neutral form of Cl, is still unstable with a 7-electron valence configuration

3 0

3 years ago