Zadania z chemii IB SL

(i) State the number of protons, electrons and neutrons in $\ce{^{85}Rb+}$. (ii) State the full electron configuration for $\ce{^{85}Rb+}$. (iii) The relative atomic mass, $A_r$, of Rb is 85.47. Isotope Mass Percent abundance $\ce{^{x}Rb}$ 72.17 %…

A beam containing protons, neutrons and electrons is passed between two charged metal plates. The three paths observed are labelled P, Q and R. Which row correctly identifies the particle following each path? A. P: electron, Q: proton, R: neutron B. P: proton,…

The letters below stand for four species, not for element symbols. Which pair of species has an identical number of outer-shell electrons? $\ce{^{31}_{15}J^{2-}}$, $\ce{^{40}_{18}L^{+}}$, $\ce{^{39}_{19}M^{+}}$, $\ce{^{32}_{16}Q^{2+}}$ A. J and M B. L and Q C.…

Naturally occurring gallium consists of two isotopes: 60 % of the atoms contain 38 neutrons and the remaining 40 % contain 40 neutrons. (i) Use section 7 of the data booklet to deduce the nuclear symbol of the heavier isotope. (ii) Calculate the relative…

Which set correctly shows the numbers of protons, neutrons and electrons in $\ce{^{65}Cu^2+}$? A. Protons 29, neutrons 36, electrons 31 B. Protons 29, neutrons 36, electrons 27 C. Protons 27, neutrons 65, electrons 27 D. Protons 65, neutrons 65, electrons 29

What is the number of subatomic particles in $\ce{^{88}Sr^2+}$? A. Protons: 40, neutrons: 50, electrons: 36 B. Protons: 38, neutrons: 50, electrons: 36 C. Protons: 38, neutrons: 88, electrons: 40 D. Protons: 40, neutrons: 88, electrons: 40

At 25 °C the density of heavy water, $\ce{^{2}H2O(l)}$, is $1.11\ \mathrm{g\,cm^{-3}}$, while the density of ordinary water, $\ce{^{1}H2O(l)}$, is $1.00\ \mathrm{g\,cm^{-3}}$. Which statement explains this difference? A. Each $\ce{^{2}H}$ nucleus contains one…

In the Geiger–Marsden experiment, α-particles (the nuclei of helium-4 atoms) were fired at a very thin foil of silver. A detector that could be moved around the foil recorded the angle of deflection, θ, of the particles. Two of the possible routes are shown:…

Outline why the scientific model of the atom has been modified several times since it was first proposed.