Atomic Structure & Bonding Flashcards

Question

Why does reactivity increace as you go down the alkali metals?

Answer 1

- As you go down the group, there is a weaker attraction between the outer electron and the nucleus because they are further apart - The outer electron is also sheilded from the nucleus by the internal energy shells - This makes it easier to loose the electron, which means it is more reactive.

Answer 2

A group 1 element that, - is soft (can be cut with a knife) - have relatively low boiling points and densities - reacts rapidly with water, oxygen and chlorine - as you go down the group, reactivity increaces

Answer 3

- When reacted with chlorine, a metal chloride is produced. This dissolves in water and produces a colorless solution - When reacted with oxygen, a metal oxide is produced which makes the metal appear dull rather than shiny - When reacted with water, a hydrogen and metal hydroxide is produced, which is an aqueous, alkali solution. The energy released from the reaction is great enough to melt the metal.

Answer 4

- less reactive compared to g1 elements - high boiling point (except mercury) - strong and hard - dense - can form ions with **different** positive charges (e.g, 2+, 3+ 4+) - can form colored compoundes (e.g, Iron (III) oxide is red) - can be used as a catalyst

Answer 5

Because it has no delocalized electrons (1) or ions to carry the charge. (1)

Answer 6

**Coarse Particles** - Dust, PM₁₀, 2,500 - 10,000 nm in diameter **Fine Particles** - Particulate matter, PM₂.₅, 100 - 2,500 nm in diameter **Nanoparticles** - 1-100 nm in diameter

Answer 7

As the particle decreaces by 10x in size, It increaces by 10x in surface area : volume ratio.

Answer 8

Because nanoparticles are so small compared to normal particles, they have a high surface area to volume ratio. With this higher surface area, a smaller amount is needed to fuffil its function.

Answer 9

**Advantages** 1. Changes the properties of a material 2. High surface area, so effective catalysts 3. Changes the original properties of the material, so versatile 4. Transparency in sunscream **Disadvantages** 1. Can enter bloodstream when applied onto skin 2. We do not yet know the long-term effects 3. Large surface area causes some nanoparticles to be reactive and explosive 4. Can easily become airborne and damage the lungs

Answer 10

- The round bottom flask is heated (e.g, with a bunsen burner). The substances in the mixture begin to evaporate. - The substance with a lower boiling point will evaporate more easily - When the substances hit the fractionating collum, they condense back into the flask. This repeats and increases the amount of the substance with a lower boiling point - As they pass the themometer, the temperature rises - Once this reaches the boiling point of the substance with a lower boiling point, only that substances goes through the condenser and drips out into the conical flask as a pure substance. - This is repeated, but with a higher boiling point for the other substances within the mixture.

Answer 11

- He put it in order of increasing atomic weight (now known as mass number) - He then switched around the orders of the elements so that elements with similar properties could be grouped together - He then left gaps in his periodic table, as he realised there were elements that had not yet been discovered.

Answer 12

- Mendeleev had ordered it in terms of atomic weight (mass number) as atomic number (the number of protons) had not yet been discovered. *[This meant that some elements would be in the wrong order, due to the presence of isotopes]* - The modern periodic table contains group 0 elements (noble gasses). These had not been fully discovered when Mendeleev made his periodic table.

Answer 13

**Döbereiner** - Triads - He noticed that elements with similar properties often came in groups of 3 (e.g, chlorine, bromine, iodine are all reactive non-metals) **Newlands** - Law of Eighths - He noticed that when you order the elements in terms of increasing atomic weight (mass number), every 8th element would react in a similar way

Answer 14

- As you go down the group, there is a weaker attraction between the outer electron and the nucleus because they are further apart - The outer electron is also sheilded from the nucleus by the internal energy shells - This makes it easier to loose the electron, which means it is more reactive.