How do the physical properties of nonmetals differ from the physical properties of metals?
Here is a good site that will give you all of the information you seek. Study it carefully.
http://chemed.chem.purdue.edu/demos/main_pages/2.2.html
Which group of elements are all gases at room temperature?
Look at group 18 or the periodic table.
http://www.webelements.com/
To understand how the physical properties of nonmetals differ from metals, we need to explore the characteristics of both groups.
1. Electrical conductivity: Metals are generally good conductors of electricity due to the presence of a large number of free electrons that can move easily. Nonmetals, on the other hand, have fewer free electrons, making them poor conductors of electricity.
2. Thermal conductivity: Similar to electrical conductivity, metals are also good conductors of heat. This is because their free electrons can transfer thermal energy efficiently. Nonmetals, however, have lower thermal conductivity as they lack these free electrons.
3. Malleability and ductility: Metals are malleable, meaning they can be hammered or bent into various shapes without breaking. They are also ductile, which means they can be drawn into thin wires. Nonmetals, in contrast, are generally brittle and tend to shatter when subjected to pressure.
4. Luster: Metals often have a characteristic luster or shine due to their ability to reflect light. Nonmetals, on the other hand, may appear dull or have a more non-reflective surface.
5. Melting and boiling points: While there are exceptions, metals generally have higher melting and boiling points compared to nonmetals. This is because the metallic bonds that hold metal atoms together are stronger and require more energy to break.
To obtain a comprehensive understanding of the physical properties of nonmetals and metals, it is useful to refer to the periodic table. The periodic table is a valuable tool that categorizes elements based on their atomic properties and can provide further insights into their physical and chemical behavior.