![]() ![]() Calcium oxide that survives processing without reacting in building products, such as cement, is called free lime. By contrast, quicklime specifically applies to the single compound calcium oxide. The broadly used term lime connotes calcium-containing inorganic compounds, in which carbonates, oxides, and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. It is a white, caustic, alkaline, crystalline solid at room temperature. How does the reactivity of non–metals change in a period and group?Īns: Reactivity generally represents the property of non-metals which measures its tendency to gain electrons.Calcium oxide ( formula: Ca O), commonly known as quicklime or burnt lime, is a widely used chemical compound. Predict the position of the element in the periodic table satisfying the electronic configuration $(n-1)$ 11 protons are present which exert higher effective nuclear charge and the tendency of removing an electron is quite difficult as compare to Ne as it has only 10 protons.ġ3. What is the electronic configuration when elements are classified group-wise?Īns: Those elements which are in the same group have the same number of valence electrons and also show similar physical and chemical properties.ġ0. The seventh period is incomplete it starts with francium having atomic number 87 and up to 93 onwards are purely synthetic in nature and are called transuranium elements.Īns: Electronic configuration defines how electrons are distributed into orbitals of an atom.ĩ. The sixth period contains 32 elements starting from caesium and the last one is radon and is said to be the longest period. The fourth and fifth periods both contain 18 elements from potassium to krypton in the fourth and rubidium to xenon in the fifth period these are long periods. ![]() The second and third periods both contain 8 elements from lithium to neon in the second period while from sodium to argon in the third period. In short, give the features of the seven periods.Īns: The first period is said to be the shortest period containing only two elements hydrogen and helium. The elements present in groups 3-12 are called transition elements.ħ. The elements present in groups 1, 2 and 13-17 are called main group elements. Seven horizontal rows are known by the name periods. ![]() Their groups are numbered from left to right as 1-18. Give the general characteristics of the long form of the Modern periodic table?Īns: General characteristics of the long form of Periodic table can be discussed as follows: Define and state Mendeleev’s periodic law.Īns: This law states that elements are arranged according to their atomic weight.Ħ. What is the basis of the triad formation of elements?Īns: Triad formation is basically dependent upon the middle element which represents that the atomic weight of the middle one is the half of the other two elements of the triad which are in between these two elements and this relationship is also given by Dobereiner know as the law of triads.Īns: Elements are arranged according to their physical and chemical properties and with the increase in atomic numbers.ĥ. Who was the first scientist to classify elements according to their properties?Īns: In the year 1829, a German scientist named Johann Dobereiner was the first one who classified elements according to their properties.ģ. How many elements are known at present?Īns: At present 114 elements are known to us.Ģ. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |