![]() This bundle comes complete with fully differentiated and resourced lessons from the topic. Perfect for KS3 Chemistry! Created for the AQA Activate 1&2 unit 5: Matter. Following this pattern, cesium is shown to have the largest atomic radius.Matter AQA Activate 1&2 KS3 Science Bundle ![]() Through Periodic trends, the atomic radius increases in size further left of a period, and lower down a group. Several factors affect this distance including the number of an element, and the number of electron shells. Atomic Radius:Ītomic Radius is a term describing the distance between an atom’s nucleus, and its outermost electron shell. The larger space in chlorine’s orbital causes its electrons to be more susceptible to share the space with an extra electron, increasing the electron affinity. This is due to chlorine having more space for electrons than fluorine in its outermost orbital. An exception to this rule is with the element with the highest electron affinity, chlorine. This is seen as the electrons that form the negative ions are added to the outer electron shell, causing an increased attraction between the electrons and the nucleus. A trend is observed, as elements further right a period and higher up a group have an increased electron affinity. ![]() In this process, energy is released, also known as an exothermic process (excluding noble gases). Electron Affinity:Įlectron Affinity is a property describing the tendency of a neutral atom to gain an electron, in order to form a negative ion. Note: This applies to groups 1,2 (metals) and to groups 15,16, and 17 (non-metals). The most highly reactive element to be observed is cesium, as it spontaneously reacts with air and water! On the other hand, reactivity in non-metals increase further right down a period, and further up a group. The reactivity of metals increases further left along a period, and further down a group. Reactivity is dependent on the classification of an element (metals and non-metals), as they both have differing periodic trends. These are factors that affect the interactions of electrons that chemical reactions undergo. This property is dependent on characteristics such as electronegativity and ionization energy. Reactivity describes the ability of a molecule or atom to undergo a chemical reaction, followed by a release in energy. This allows for electrons to be retained as a result of these attractive forces. An example of high ionization energy is in helium, as it has a very small atomic radius with +2 charge present in the nucleus. The Ionization energy increases further right down the period, and higher up a group as more energy is required to remove a tightly bounded electron from the atom. This property is describing the difficulty of removing an electron. The minimum amount of energy required to remove an electron from a neutral atom’s outermost electron shell in the gaseous phase is called the ionization energy. Note: This periodic trend excludes the Noble gases (Group 18). Note that the noble gases do not have an electronegativity. This is observed through Periodic Trends, as the further right of a period, and higher up a group are observed to have increased values in electronegativity. This scale ranges from 0.7 to 4.0, where cesium is the least electronegative element, and with fluorine being the most electronegative element. It was created by measuring the bond energy of the different elements joined by covalent bonding. The scale that was formed in order to measure this property is the Pauling scale. ![]() Which properties can be identified using periodic trends? Electronegativity:Įlectronegativity is a property that measures the tendency of an atom to attract electrons to form a bond. We discuss trends for properties such as electronegativity, atomic radius, first ionization energy, reactivity and electron affinity. This is due to the structural similarities’ elements have within a period or family that allows for these trends to take place. ![]() These trends have allowed scientists in the past to predict certain characteristics of unknown elements. Periodic trends are observable patterns in the properties of an element that are dependent on its position in the Periodic Table. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |