Define electronegativity - Leaving Cert Chemistry - Question 11 - 2015

The increase in electronegativity from gallium to germanium can be attributed to two main factors:

1. Nuclear Charge: The nuclear charge, which is the number of protons in the nucleus, increases as we move from gallium to germanium. This results in a stronger attraction between the nucleus and the electrons, raising the electronegativity.

2. Atomic Radius: The atomic radius decreases as we move up the periodic table. A smaller atomic radius means that the valence electrons are held closer to the nucleus, which also contributes to higher electronegativity.

Mendeleev predicted the properties of the elements gallium and germanium based on:

1. Arrangement of Elements: He arranged the known elements in columns and groups based on their atomic weight.

2. Similar Properties: He recognized that elements with similar properties were found in the same group, allowing him to predict the existence and properties of undiscovered elements by looking for gaps in his table.

3. Trends: By observing trends in the properties of known elements (like increasing atomic weight), he extrapolated information about elements that had not yet been discovered, explaining their expected behavior and properties.

The molecular formula for the simplest compound formed between germanium(IV) and hydrogen is GeH₄.

No, I would not expect GeH₄ to be water soluble. This compound is classified as a non-polar solute, similar to other compounds like methane (CH₄) and silane (SiH₄). Non-polar molecules do not interact well with polar solvents like water, which is why GeH₄ would not dissolve significantly in water.