Zadania z chemii IB SL

Why is the first ionization energy of sulfur greater than that of magnesium? A. The outer electrons of sulfur are further from the nucleus. B. Sulfur atoms have more occupied main energy levels. C. Sulfur atoms have a greater nuclear charge, while the…

Which electron configuration is correct for a chromium atom, Cr, in its ground state? A. $\mathrm{[Ar]\,4s^1\,3d^5}$ B. $\mathrm{[Ar]\,4s^2\,3d^4}$ C. $\mathrm{[Ar]\,3d^6}$ D. $\mathrm{[Ar]\,4s^2\,4d^4}$

Simple bonding theory expects every atom in a covalent molecule to end up with eight valence electrons. Two stable gas-phase molecules, $\ce{BF3(g)}$ and $\ce{BeF2(g)}$, do not fit this picture. Which adaptation of the bonding model was needed to explain…

What is the oxidation state of chlorine in $\ce{Cl2O7}$? A. $-7$ B. $+3.5$ C. $+7$ D. $+14$

Which pair of elements reacts together most vigorously? A. Sodium and bromine B. Potassium and bromine C. Sodium and chlorine D. Potassium and chlorine

Phosphorus occurs as the atom and as several ions. In which row are the species arranged from the smallest radius to the largest? A. $\ce{P^{3-}}$, $\ce{P}$, $\ce{P^{3+}}$, $\ce{P^{5+}}$ B. $\ce{P^{5+}}$, $\ce{P^{3+}}$, $\ce{P}$, $\ce{P^{3-}}$ C. $\ce{P}$,…

Butanone, $\ce{CH3COCH2CH3}$, has the structure shown. One of the following four compounds shares its molecular formula, $\ce{C4H8O}$, with butanone. Which compound is this structural isomer of butanone? A. $\ce{CH3COCH2CH2CH3}$ B. $\ce{CH3CH2CH2CHO}$ C.…

In which species does an atom have the oxidation state +5? I. $\ce{IF5}$ II. $\ce{H3PO4}$ III. $\ce{N2O4}$ A. I and II only B. I and III only C. II and III only D. I, II and III

Which statement explains why the atomic radius decreases across period 3 from magnesium, Mg, to sulfur, S? A. The number of occupied main energy levels increases B. The shielding effect of the inner electrons decreases C. The number of protons in the nucleus…