Zadania z chemii IB HL

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…

Heavy water, $\ce{^{2}H2O}$, boils at 101.4 °C, whereas ordinary water, $\ce{^{1}H2O}$, boils at 100.0 °C at the same pressure. Which statement is correct? A. The boiling points differ because $\ce{^{2}H2O}$ molecules have a greater mass, while the chemical…

α-particles are the nuclei of helium-4 atoms. In an experiment based on the work of Geiger and Marsden, a beam of α-particles is directed at a very thin platinum foil and the angle of deflection, θ, of each particle is recorded by a detector that can be moved…

Outline why scientists have replaced earlier models of the atom with new ones.