Periodic law states that when the elements are arranged according to their atomic numbers, this allows elements with similar properties to appear at regular intervals. predict the group of elements and their number of valence electrons that will combine in a 3: 2 ratio to with calcium. a) boron, aluminum, gallium; 3 b) sulfur, selenium, polonium; 6 c) oxygen, tellurium, bismuth; 2 d) nitrogen, phosphorus, arsenic; 5

The correct answer is Option D.

Explanation:

Calcium is the 20th element of the periodic table having electronic configuration

This element will loose 2 electrons easily to form stable configuration. This is a metal and will form an ionic bond with a non-metal.

From the given options:

Option A: boron, aluminum, gallium; 3

These elements belong to Group 13 and are considered as metals having oxidation state of +3 because they easily loose 3 electrons. Thus, they will not form any compound with calcium.

Option B: sulfur, selenium, polonium; 6

These elements belong to Group 16 and are considered as non-metals having oxidation state of -2 because they easily gain 2 electrons. Thus, they form compound with calcium but in a 1 : 1 ratio.

Option C: oxygen, tellurium, bismuth; 6

These elements belong to Group 16 and are considered as non-metals having oxidation state of -2 because they easily gain 2 electrons. Thus, they form compound with calcium but in a 1 : 1 ratio.

Option D: nitrogen, phosphorus, arsenic; 5

These elements belong to Group 15 and are considered as non-metals having oxidation state of -3 because they easily gain 3 electrons. Thus, they form compound with calcium in a 3 : 2 ratio.

Hence, the correct answer is Option D.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml