Advertisements
Advertisements
प्रश्न
Atomic number of metal ‚A‛ is 11, while atomic number of metal ‚B‛ is 20. Which of them will be more reactive? Write the chemical reaction of dilute HCl with metal ‚A‛.
Advertisements
उत्तर
Metal ‘A’ is more reactive than metal ‘B’.
Atomic number of metal ‘A’ is 11, hence it is Na.
`2Na + 2HCI → 2NaCI(aq) + H_2 (g) `
APPEARS IN
संबंधित प्रश्न
The atomic masses of three elements A, B and C having similar chemical properties are 7, 23 and 39, respectively.
- Calculate the average atomic mass of elements A and C.
- Compare the average atomic mass with atomic mass of B.
- What could the elements A, B and C be?
Study the following table in which positions of six elements A, B, C, D, E and F are shown as they are in the modern periodic table:
|
Group→
Period↓ |
1
|
2
|
3-12
|
13
|
14
|
15
|
16
|
17
|
18
|
| 2 | A | B | C | ||||||
| 3 | D | E | F |
On the basis of the above table, answer the following questions:-
(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of D and E, which is bigger in size and why?
(v) Write the common name for the family to which the elements C and F belong.
An element 'M' with electronic configuration (2, 8, 2) combines separately with (NO3)–, (SO4)2– and (PO4)3– radicals. Write the formula of the three compounds so formed. To which group and period of the Modern Periodic Table does the element 'M' belong? Will 'M' form covalent or ionic compounds? Give reason to justify your answer.
How many groups and periods are there in the modern periodic table?
Consider two elements 'X' (Atomic number 17) and 'Y' (Atomic number 20)
(i) Write the positions of these elements in the modern periodic table giving justification.
(ii) Write the formula of the compound formed by the combination of 'X' and 'Y'.
(iii) Draw the electron-dot structure of the compound formed and state the nature of the bond formed between the two elements ?
Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)
The following table shows the electronic configuration of the elements W, X, Y, Z:
| Element | w | x | y | z |
| Electronic configurations |
2, 8, 1 | 2, 8, 7 | 2, 5 | 1 |
Answer the following questions based on the table above:
1) What type of Bond is formed between :
a) W and X
b) Y and Z
2) What is the formula of the compound formed between :
a) X and Z
b) W and X
An element Z has atomic number 16. Answer the following questions on Z:
1) State the period and group to which Z belongs
2) Is Z a metal or a non-metal?
3) State the formula between Z and hydrogen
4) What kind of a compound is this?
Why do elements in the same group show similar properties but the elements in different groups show different properties?
The electronic configuration of the atom of an element X is 2, 8, 4. In modern periodic table, the element X is places in :
(a) 2nd group
(b) 4th group
(c) 14th group
(d) 8th group
The correct increasing order of the atomic radii of the elements oxygen, fluorine and nitrogen is:
(a) O, F, N
(b) N, F, O
(c) O, N, F
(d) F, O, N
Which of the following set of elements is written correctly in the order of their increasing metallic character?
(a) Mg, Al, Si
(b) C, O, N
(c) Na, Li, K
(d) Be, Mg, Ca
In each of the following pair, choose the atom having the bigger size:
(a) Mg (At. No.12) or Cl (At. No.17)
Periodicity is observed due to the similar ______.
An element barium has atomic number 56. Look up its position in the periodic table and answer the following question.
Is it more or less reactive than calcium?
An element 'M' has atomic number 11.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
How do you calculate the possible valency of an element from the electronic configuration of its atoms?
Fill in the blank
Oxidising property ________from fluroine to iodine because the power to accpet electron decreases.
How could the atomic radius of a noble gas be compared with the other elements in a period?
What is the common feature of electronic configurations of the elements at the end of period 2 and period 3?
What is meant by a group in the periodic table?
Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide.
Arrange the following as per instruction given in the bracket.
Cl, F, Br, I (increasing electron affinity)
Arrange the following as per instruction given in the bracket.
Cs, Na, Li, K, Rb (decreasing electronegativity)
The elements of one short period of the periodic table are given below in order from left to right:
| Li | Be | B | C | O | F | Ne |
One element of this period is missing. Which is the missing element and where should it be placed?
The elements of one short period of the periodic table are given below in order from left to right:
| Li | Be | B | C | O | F | Ne |
Place the three elements fluorine, beryllium and nitrogen in the order of increasing electronegativity.
Atomic numbers of elements A, B, C, D, E, F are 8, 7, 11, 12, 13 and 9 respectively. State the type of ions they form.
An element belongs to the third period and Group IIIA (13) of the periodic table. State: if it is a metal or non-metal?
Moving left to right in the second period, the number of valence electrons _____.
An element A has 2 electrons in its fourth shell. State:
position in the periodic table
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
The electronic configuration of an element is 2, 8, 4. State it:
name and write its one physical property.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Compound formed when an element A of group 2 combines with an element B of group seventeen.
Name the period which is the shortest period of the periodic table.
Name or state following with reference to the elements of the first three periods of the periodic table.
The number of electron shells in elements of period 1, period 2, and period 3.
Name or state following with reference to the element of the first three periods of the periodic table.
The non-metallic element present in period 3 other than sulphur and chlorine.
Name or state following with reference to the element of the first three periods of the periodic table.
A non-metal in period 2 which is tetravalent.
