In 1869, Mendeleev published his early periodic table based on relative atomic mass, but had to swap the positions of certain elements to ensure elements with similar properties were grouped together.
Explain, in terms of subatomic particles and isotopes, why ordering elements strictly by relative atomic mass (ArA_rAr) does not always correspond to their correct order by atomic number (ZZZ).
Give the chemical symbols of two adjacent elements in the ddd-block of the Periodic Table where the element with the higher atomic number has a lower relative atomic mass than the element preceding it.
The diagram below shows a simplified version of the modern periodic table. The letters V, X, Y, and Z are temporary labels and do not represent the actual chemical symbols of the elements.
Which of the elements represented by V, X, Y, or Z forms a stable ion with a 2+2+2+ charge and reacts slowly with cold water but rapidly with steam? Explain your answer with reference to its position in the periodic table.
The diagram below shows a simplified version of the modern periodic table. The letters V, X, Y, and Z are temporary labels and do not represent the actual chemical symbols of the elements.
Which of the elements represented by V, X, Y, or Z is a diatomic non-metal at room temperature that forms a 1−1-1− ion when reacting with metals? Explain your answer with reference to its position in the periodic table.