These repel the outer shell electron (like charges repel) therefore pushing it away. As elements get bigger, they have a higher level of reactivity. As elements get bigger, they have a higher level of reactivity. As we go down the group, the atom gets bigger. The reactivity of group 1 metals increases as you go down the group because: 1) The atomic radius increases. All you really need to know is that the reactivity increases because the activation energy for the reactions falls. Group 1 metals all have one electron in their outer shell. The quote from your text: So the stability that you are referring to is thermal stability.This is an important detail. One to one online tution can be a great way to brush up on your Chemistry knowledge. It isn't clear from the syllabus that you need this explanation, but look at it anyway. When they do react they produce hydroxides and hydrogen. 2, why does the reactivity of elements in group 7(florine,chorine) decrease as you continue down the group? It reacts with cold water to produce an alkaline solution of calcium hydroxide and hydrogen gas is released. For similar reasons the electronegativity decreases. This means that the electrostatic forces of attraction between the outer shell electron and the nucleus are weaker and therefore it takes less energy for the electron to be lost. The answer to your question is quite simple.The alkali metals of group 1 grow larger in size downwards and since the effective nuclear charge remains the same as we go down group 1 the number of shells also increases and so it is easy to lose an electron and therefore as we move downwards the reactivity … Electrons present in the outermost shell of an atom are called valence electrons … Is as follows: To remember how the reactivity of the alkali metals and halogens increases or decreases, put a pin in the middle of the periodic table and spin it anti-clockwise. This is because as the ions get larger the distance between the bonding electrons and the positive nucleus gets larger and reduces the overall attraction between the two. Melting point and boiling point increase down Group 17 from top to bottom. This is also a good measure of reactivity, because the more that an element attracts electrons, the more reactive it is. The hydroxide solubilities increase down the group. The carbonates become more stable to heat as you go down the Group. So reactivity increases. Group 1 elements increase in chemical reactivity as you go down the group from top to bottom. Generally the melting point of the alkali metals decreases down the group. Hence the attraction between nucleus and electrons decreases down the group. Hence the attraction between nucleus and electrons decreases down the group. Atoms get bigger so electrons are not held as tightly and are lost more easily. Ionisation is a reaction so ionisation energy decreases as reactivity increases. the radii increase as we go down in a gp . Explaining the increase in reactivity down the group. F is more reactive than Cl etc. 1) As you move down a group, lattice energy decreases. The reactivity all increases as you go down the periodic table, for example rubidium is far more reactive than sodium. Trend of Reactivity in Group 1 Metals: The Reactivity of Group 1 Metals will increase down the group; As you go down the group, the observations during the reaction with air and water becomes more vigorous We saw the reactions, now we discuss why they actually get more reactive down the group. Reactivity increases down the group. That is why as you go up a group Chemical Reactivity increases because it is easier for elements to gain electrons when they have high electronegativity. Show the electron shell including the s, p, and d orbitals together. The general reactivity of halogens decreases down the group due to the increase in the number of filled electron shells. Have a Free Meeting with one of our hand picked tutors from the UK’s top universities. As I said earlier, they are powerful reducing agen… So the reactivity of non metal decreases down the group . Mg(s) + H2O(g) → MgO(s) + H2(g) b) Calcium is more reactive. Non-metal atoms gain electrons when they react with metals. Ca(s) + H2O(l) → Ca(OH)2(aq) + H2(g) The melting and boiling points increase as you descend the group; they are more highly coloured as you go down the group; they form acidic compounds with hydrogen and so on. It's how resistant a molecule is to decomposition at higher temperatures. They react with water to produce an alkaline metal hydroxide solution and hydrogen. We have evidence for the stability of the electronic configuration of the group 1 cations based on inspection of the values for the second ionisation for this group. WHY? As you go down the group, there are more inner electrons. I'll try not to make this confusing: 1. Explain why magnesium chloride has a high melting point. This is clearly seen if we observe the reactions of magnesium and calcium in water. Now on moving down the group , the size of atom increases due to addition of atomic shells due to this , the tendency of an atom to gain electron decreases down the group due to decrease in nuclear charge . This means that it takes less energy to remove this electron. Because solubility increases down the group, the pH of a saturated solution increases down the group. The general reactivity of halogens decreases down the group due to the increase in the number of filled electron shells. The reactivity of these metals increases going down the group. Reactions compared The table shows the main observations when lithium, sodium and potassium are added to water. Calcium hydroxide is mainly formed as a white precipitate (although some does dissolve). Less precipitate is formed down the group with increasing solubility. therefore the reactivity decreases down the group. The reactivity increases as you go down a group.This is because the number of shells increases and so the effective nuclear charge on the valence electrons decreases.the valence electrons are in the outermost shell so they can be lost easily. A hint: BaSH MgSS (say it as BASH MAGS) Chemical reactivity of group 17 elements decreases down group 17 from top to bottom. The Group II elements are powerful reducing agents. Nitrogen reacts with hydrogen to produce ammonia. Magnesium chloride is an ionic compound and has a high melting point. Not sure if I would put H in group 1. All the nitrates in this Group undergo thermal decomposition to give the metal oxide, nitrogen dioxide and oxygen. a gp the removal of electron require less energy .therefore reactivity increases. Group 1 & 7 elements are missing 1 electron from their valance shell making them highly votile and reactive. The reactions of the elements with water become more vigorous down the group. Progressing down group 1, the atomic radius increases due to the extra shell of electrons for each element. That is why as you go up a group Chemical Reactivity increases because it is easier for elements to gain electrons when they have high electronegativity. Valence Electrons. The effect of heat on the Group 2 nitrates. The reactions proceed faster as the energy needed to form positive ions falls. When a halogen atom reacts, it gains one electron into their highest occupied energy level (outer shell) to form a singly negative charged ion. Summarising the reason for the increase in reactivity as you go down the Group. This is in part due to a decrease in ionization energy down the group, and in part to a decrease in atomization energy reflecting weaker metallic bonds … First ionization energy decreases down group 17 from top to bottom. The hydroxides all react with acids to make salts. Why does reactivity increase as you go down Group 1 metals? - The atomic radius increases as you move down a group. Calculate the mass of ammonia made from 84.0g of nitrogen. So what is thermal stability? Elements become darker in colour going down group … The atom is held together by strong electrostatic forces of attraction between the positive protons in the nucleus and negative electrons. The distance "c" is greater than "a" and the force of attraction between the nucleus and … I get why it does in group 1, but I don't get why it does in group 7?? The atom is held together by strong electrostatic forces of attraction between the positive protons in the nucleus and negative electrons. a) Virtually no reaction occurs between magnesium and cold water. Group 1 & 7 elements are missing 1 electron from their valance shell making them highly votile and reactive. Explain why the reactivity of elements in group 1 increases down the group but decrease in group 7 down the group, Electron affinity trend;why does it decrease down a group, Electronegativity and ionnisation energy trend in the periodic table, Periodic Trend Explanation about atomic radius. Explaining the increase in reactivity down the group The reactions proceed faster as the energy needed to form positive ions falls. This is in part due to a decrease in ionization energy down the group, and in part to a decrease in atomization energy reflecting weaker metallic bonds … As you go down the group, the outer shell electron is further away from the positive nucleus. It helps to think about the size of an atom with the location of the electrons and nucleus in mind. Since there is only one electron to lose, group 1 metals are all extrememely reactive. We have evidence for the stability of the electronic configuration of the group 1 cations based on inspection of the values for the second ionisation for this group. Attractive force of nucleus is greater with smaller atoms (protons closer to the outer shell and there is less shielding effect of inner shell. it means it is easy to form an ion. Alkali metals from lithium to potassium get more reactive because the force of attraction between the nucleus (core) and the outer electron gets weaker as you go down group 1 elements. All group 1 metals have one electron in its outer shell. Thermodynamic Properties of the Reactions Group 1 elements increase in chemical reactivity as you go down the group from top to bottom. However, in a reaction with steam it forms magnesium oxide and hydrogen. Group 1 elements are known as Alkali Metals. Chemical Reactivity  decrease as you go down  the For Non-Metals, the farther right-up in the table you go, the higher the electronegativity. Since the square of the distance is inversely proportional to the force of attraction, lattice energy decreases as the atomic radius increases. Describe the structure and bonding of sodium chloride. In group 7 atoms get bigger down the group. The larger an atom is, the more reactive it will be. Atoms get bigger so electrons are not held as tightly and are lost more easily. Explaining trends in reactivity. Why do the reactivity of the group 1 atoms increase as you go down the group, but the reactivity of group 7 decreases as you go down the group. The solubilities of the hydroxides of the elements increase going down the group. Electronegativity: This property determines how much the element attracts electrons. Look at this page again, and this time read the explanation for the increase in reactivity as you go down the group. As you go up group 7 (the halogens), again the elements get more reactive. The electrons in the outer shell move further away from the nucleus as we go down the group and the attraction force between the electrons and the nucleus become weaker and weaker. Hydrogen - Hydrogen - Reactivity of hydrogen: One molecule of hydrogen dissociates into two atoms (H2 → 2H) when an energy equal to or greater than the dissociation energy (i.e., the amount of energy required to break the bond that holds together the atoms in the molecule) is supplied. This attraction helps stabilize the atom. The answer to your question is quite simple.The alkali metals of group 1 grow larger in size downwards and since the effective nuclear charge remains the same as we go down group 1 the number of shells also increases and so it is easy to lose an electron and therefore as we move downwards the reactivity … As you go down group 1 (the alkali metals) in the periodic table, the elements get more reactive. Reactivity increases down the group. due to ionization energy decreases . Metals react by losing electrons so larger atoms lose electrons more readily as the outer electrons are further from nucleus and less attracted. As we go down the group, an additional electron shell is added thereby increasing the atomic radii of the atom. The solubilities of the sulphates of the elements decreases down the group. 1,why does the reactivity of elements in group 1 (hydrogen,lithium,sodium,pottasium)increase as you continue down? On the reaction profile below, label the activation energy and the energy given out ((delta)H) - 2 marks. I'll try not to make this confusing: 1. The answer lies in understanding what the atoms are trying to do. The reactivity of group 1& 7 elements differ as you move down the periods. The reactivity of group 1& 7 elements differ as you move down the periods. Example - potassium(K) in the 4th period is more reactive than lithium(Li) in the 2nd period in group 1 I know why group 1 reactivity increases as you go down the group but I am confused on group 7 and why it is different? so the reactivity increases .as we go down in . You know that protons are positively charged and electrons are negatively charged, therefore there is a level of attraction between these two oppositely charged subatomic particles. e.g. A reducing agent is the compound that gets oxidised in the reaction and, therefore, loses electrons. The group 1 elements are all soft, reactive metals with low melting points. The reactions become easier as the energy needed to form positive ions falls. This is mainly due to a decrease in ionisation energy as you go down the Group. When they react they form positive metal ions by losing this electron. As you go down the group, the outer shell electron is further away from the positive nucleus. The reactivity of Group 7 elements decreases down the group. 2, why does the reactivity of elements in group 7 (florine,chorine) decrease as you continue down the group? They are called s-block elements because their highest energy electrons appear in the s subshell. Going down the group, the first ionisation energy decreases. An atom is made in such a way that the nucleus with the positive charges (protons) is in the centre and the negative charge (electrons) are arranged in shells around it. This leads to lower activation energies, and therefore faster reactions. As you go down the Group, the carbonates have to be heated more strongly before they will decompose. since electrons are less easy to be accepted by the halogen atoms, the tendency for the atoms to form ions decreases down the group. Could someone please help me understand trends????? Chemical Reactivity  decrease as you go down  the For Non-Metals, the farther right-up in the table you go, the higher the electronegativity. 2) There are more inner electrons which repel the outer shell electron. 1,why does the reactivity of elements in group 1 (hydrogen,lithium,sodium,pottasium)increase as you continue down? © 2021 Yeah Chemistry, All rights reserved. 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