Moving from left to right across a period, the elements become less metallic. This is related to the increase in the number of electrons in the outer shell of their atoms. The atoms become more likely to gain or share electrons, rather than lose them when they form compounds.
There are some exceptions though. For example, mercury is a liquid at room temperature. The metals in Group 1, such as lithium, sodium and potassium, are all soft.
Non-metals have a variety of properties, but very few are good conductors of electricity. Graphite (a form of carbon) is a rare example of a non-metal that conducts electricity very well.
Many non-metals have low melting and boiling points. When non-metals are in a solid state, they are usually brittle so you can’t beat them into shape.
Some elements between the metals and non-metals in the periodic table have properties which are a mixture of the properties of metals and non-metals. These elements are called metalloids or semi-metals.These elements are found close to the zig-zag line that separates the metals from the non-metals.