Classification of Elements & Periodicity in Properties Test 6

Elements of group 1, i.e. Li, Na, K, Rb, Cs and Fr, are called alkali metals because they react with water to form alkaline solutions. The pH of solutions usually range between 8-12. 

The six noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Their atomic numbers are, respectively, 2, 10, 18, 36, 54, and 86.

The metallic character of group 14 elements increases from top to bottom because removal of electron becomes easier on moving down the group. Metallic character increases as you move down an element group in the periodic table. This is because electrons become easier to lose as the atomic radius increases, where there is less attraction between the nucleus and the valence electrons because of the increased distance between them.

The electronic configuration of B is 1s² 2s² 2p⁶ 3s² 3p¹ and the number of electron in last p orbital is 1 so it belongs to the same group as element with configuration (1s² 2s² 2p¹).

Group 17 elements are called halogens because halogen is a Greek word which means 'salt producing'. Halogens include fluorine, chlorine, bromine, iodine andastatine. They all are non-metals. They react with metals to form compounds called salts.

Oxygen family is also known as chalcogen family when the 17 th family is known as halogen family.

The p-block elements constitute elements belonging to group 13 to 18 and these together with the s-Block elements are called Representative elements.

Transition elements are d-block elements and the characteristic electronic configuration of d block element is in option A

The periodic table is divided into four blocks that are called s, p, d, and f. Here is an explanation of each block: The s block makes up the first two columns of the periodic table. The elements in this block are all metals, and they react when water is present.

Fluorine is the highest non metallic element because it has ability to gain electrons then to donate electron because of its small size and brittle attraction to the electron of any other element therefore it gains electron rather than losing electron.

Ionic hydrides are commonly known as saline hydrides or pseudohalides. These compounds form between hydrogen and the most active metals, especially with the alkali and alkaline-earth metals of group one and two elements.

In this group, the hydrogen acts as the hydride ion (H−). They bond with more electropositive metal atoms. Ionic hydrides are usually binary compounds (i.e., only two elements in the compound) and are also insoluble in solutions. Now I hope you can form your own examples, but common examples are Sodium Hydride (NaH), Lithium hydride (LiH), Potassium hydride (KH) etc.

Elements in the long form of periodic table have been divided into four blocks i.e. s ,p ,d and f. This division is based upon the name of the orbitals which receives the last electron. 1)Elements in which the last electron enters the s orbital of their respective outermost shells are called s block elements.

Most of the f block elements, lanthanoids and actinoids are man made/synthetic/prepared in the lab. Especially actinoids.

Because of the small size of boron atom and presence of only six electrons in its valence shell, B(OH)₃ accepts a pair of electrons from OH^- ion of H₂0, releasing a proton. 

Group 1-Alkali metal,
group2- Alkali earth metals

There are two elements in the 1^st period and eight elements in the 2^nd period., The third period starts with the element with Z = 11(sodium). Now, there are nine  elements in the third period. Thus, the 3^rd period ends with the element with Z = 18(argon) i.e., the element in the 18^th group of the third period has Z = 18. Hence, the element in the 17^th group of the third period has atomic number Z = 17 ,chlorine(Cl) with atomic mass 35.453, which is a p block element.

Option ‘a’ represents metallic character of Mg. All others remaining represent nonmetals and metalloids.

The elements of "s" and "p" blocks except "d" group elements are called as representative elements. Their outer shells are not completely filled with electrons. The elements get the nearest inert gas configuration by losing or gaining or sharing of electrons. 

The elements in the group include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

The non metallic character decreases down the group.And we know the oxides of non-metal r acidic in genral.Hence acidic character of oxides decreases down d group. Down the group the size of the element increases, electronegativity decreases ,metallic character increases and hence the acidic character decrease.