Physical properties of the noble gases
The vertical column of non-metal elements on the far right of the periodic table, also called the noble gases. contains Element that is a poor conductor of electricity and heat, and which forms acidic oxides. A substance made of one type of atom only. placed in the vertical column on the far right of the A tabular representation of all known elements in order based on atomic number, eg all the noble gases are found on the right of the periodic table.. The elements in group 0 are called the The elements in group 0 of the periodic table, named for their lack of chemical reactivity.. They exist as single The smallest part of an element that can exist..
The noble gases show trends in their A description of the appearance of a substance or how it acts without involving chemical reactions. For example, state, melting point, conductivity, etc..
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Boiling points
The noble gases all have low The temperature at which a substance rapidly changes from a liquid to a gas.:
- helium, at the top of group 0, has the lowest boiling point of any element
- boiling point increases going down the group
This is because, going down group 0:
- the atoms become larger
- the Weak attractive forces between molecules. When a simple molecular substance melts or boils, it is the intermolecular forces that are broken (not the covalent bonds in each molecule). between the atoms become stronger
- more The capacity of a system to do work or the quantity required for mechanical work to take place. Measured in joules (J). For example, a man transfers 100 J of energy when moving a wheelbarrow. is needed to overcome these forces
Question
Radon is situated below xenon in group 0. Predict the likely boiling point of radon.
The actual boiling point of radon is -61.7藲C. An estimate would lie midway between -100藲C and -50藲C based on the shape of the graph.
Densities
The A measure of compactness and the ratio of mass to volume. It is usually measured in kilograms per metre cubed (kg/m3) or grams per centimetre cubed (g/cm3). of a substance is its The amount of matter an object contains. Mass is measured in kilograms (kg) or grams (g). per unit The volume of a three-dimensional shape is a measure of the amount of space or capacity it occupies, eg an average can of fizzy drink has a volume of 330 ml.. For example, a small piece of a substance with a high mass has a high density.
The A general term for a small piece of matter. For example, protons, neutrons, electrons, atoms, ions or molecules. in gases are widely spaced, so the noble gases have low densities:
- helium, at the top of group 0, has the lowest density in the group
- density increases going down the group