Understanding Atomic Theory and Chromatography

These flashcards summarize crucial concepts from the lecture on chromatography and the history of atomic theory, providing a foundation for exam preparation.

What is chromatography used for?

To separate different components of a mixture based on their solubility.

What happens to the dye during chromatography?

The dye is placed on a stationary phase and dissolves into the mobile phase, running up the page by capillary action.

What affects the movement of different colors in chromatography?

Different colors have different solubility and attraction to the stationary phase.

What is Dalton's 'Billiard Ball' Model of the atom?

It describes atoms as solid spheres that are indestructible.

What was Thomson's contribution to atomic theory?

He proposed the 'Plum Pudding' Model, which saw atoms as a mix of positive and negative charges.

What did Rutherford discover about the atomic nucleus?

He discovered that atoms have a positive nucleus surrounded by negative electrons, through his gold foil experiment.

What is Bohr's model of the atom?

It places electrons in specific shells around the nucleus.

How has the modern view of the atom evolved?

It now includes the Quantum Mechanical Model, which describes electrons in regions of probability rather than fixed orbits.

What is the significance of Ernest Rutherford's gold foil experiment?

It demonstrated that atoms have a dense, positively charged nucleus.

What defines an element's atomic number?

The number of protons in an atom's nucleus.

What is the charge of an electron?

Negative charge.

What is an isotope?

Atoms of the same element that have different numbers of neutrons.

What does the mass number of an atom represent?

The sum of protons and neutrons in the nucleus.