Presentation on theme: "Elements All matter is made up of elements. Next > All chemical substances are made up of one or more of these elements. Over 100 are known to exist. Elements."— Presentation transcript:
Elements All matter is made up of elements. Next > All chemical substances are made up of one or more of these elements. Over 100 are known to exist. Elements may combine to form compounds, but elements are the purest possible substances. This is because they cannot be transformed into other chemical substances in any normal chemical reaction.
Elements Each element is made up of ONE type of atom only. Atoms are very small. The diameter of an iron atom is just mm. The number of protons in an atom is called the ATOMIC NUMBER. This determines what element the atom is. Next > However, atoms are themselves made up of even tinier particles called protons, neutrons and electrons. Electron Neutron Proton Carbon atom (C)
To make writing about elements quicker and easier, each element has a name and its own shorthand symbol. Next > Chemical Symbols This consists of one or two letters and is often based on the Latin name of the element. Gold (Aurum) = Au 79 Au Gold Iron (Ferrum) = Fe 26 Fe Iron Ne Neon S Sulfur 32.06
The Periodic Table The Periodic Table is a list of all the different elements. The elements are specially arranged within the table so that they are categorized into groups that have similar properties. The elements are listed in order of their atomic number. This is the number of protons in the nucleus of each atom. Next > 1 H Hydrogen Atomic Number Symbol Name Relative Atomic Mass (Ar) The relative atomic mass of each element is also shown in the table. This is the average mass of one atom of the element, compared to a standard carbon atom.
1 "Each element is made up of one or more types of atoms." Is this statement true or false? Answer True or False. Question
MetalsNon-metals Period Group 0 Next > The Periodic Table The Periodic Table arranges elements in vertical columns, which are known as groups, and horizontal rows, which are known as periods.
0 IIIIVVVIVII The Periodic Table The columns in the table show the different groups. The elements in each group often have similar properties to one another. The block of elements between groups II and III are known as the transition metals. Each group is given a number. This is written as a Roman numeral, apart from the column on the far right, which is known as Group 0. Next > 0 IIIIVVVIVII
The Periodic Table The HORIZONTAL ROWS are called the PERIODS. They are also numbered, but normal numbers (not Roman numerals) are used. Next > Elements in the Periodic Table are found in order of increasing atomic number (the biggest atoms are found in the higher numbered periods)
2 What is the name given to the horizontal rows of the periodic table? Question A) Groups B) Sets C) Lines D) Periods
0 MetalsNon-metals Next > Elements in the Periodic Table The two main types of elements are the metals and the non- metals. Most of the elements in the periodic table are METALS. All the metals are found to the LEFT of the staircase-shaped line that appears toward the right of the Periodic Table.
Properties of Metals They are good conductors of heat - they allow thermal energy to be passed through them. They are also good conductors of electricity - they allow electricity to pass through them. Many are strong and tough - strong bonds are formed between the metal particles. Next > Most metals have the following physical properties in common, among others: Most metals also have high melting and boiling points, and high density.
3 Which of the following is NOT a typical metallic property? Question A) High melting and boiling point B) High density C) Poor conduction of electricity D) Good conduction of heat
Non-Metals The are much fewer non-metals than metals. Only 22 are known, and some of them are very rare. Most of the non-metals can be seen on the right side of the periodic table. The properties of non-metals are often opposite to those of metals. Next > MetalsNon- metals 0 However, hydrogen, which is found alone on the left of the table, is also a non-metal.
Properties of Non-Metals Non-metals are often poor conductors of electricity. They are known as insulators, as electric current cannot flow through them easily. Next > Many non-metals are weak and brittle (they break easily), as the non-metal structure is held together by weak forces. Many non-metals have low melting and boiling points. Eleven of them are gases at room temperature. Many non-metals have low densities. Some of the gases are lighter than air, such as the helium in balloons. Non-metals are also poor conductors of heat.
4 Which of the following is NOT a typical property of a non-metal? Question A) Poor electrical conductivity B) High boiling point C) Low density D) Poor conductivity of heat