The mass of one atom of an element X is 2.0 Γ 10β23 g.
(i) Calculate the atomic mass of element X.
(ii) What could element X be?
Mass of an atom of element X = 2.0 × 10-23g
The mass of an atom of a substance is equal to the mass of 1 mole of that substance.
As 1 mole of a substance consists of 6.022 × 1023 atoms; therefore, the mass of an atom of a substance is equal to the mass of 6.022 × 1023 atoms.
Therefore, to calculate the atomic mass of element X, we need to calculate the mass of 6.022 × 1023 atoms of X.
Mass of 1 atom of X = 2.0 × 10-23
Mass of 6.022 × 1023 atoms of X
= 6.022 × 1023 × 2.0 × 10-23
= 12 u
As Carbon has an atomic mass of 12 u; therefore, element X is carbon.
Related Articles
- The atom of an element X has 7 electrons in its M shell.(a) Write the electronic configuration of element X.(b) What is the atomic number of element X?(c) Is it a metal or a non-metal?(d) What type of ion will be formed by an atom of element X? Write the symbol of the ion formed.(e) What could element X be?
- An element X has a mass number 4 and atomic number 2. Write the valency of this element?
- The mass of one molecule of a substance is 4.65 Γ 10β23 g. What is its molecular mass? What could this substance be?
- What is meant by atomic mass, gram atomic mass of an element? Why is the mass have different expressions i.e., βuβ and βgβ?
- The atom of an element X contains 17 protons, 17 electrons, and 18 neutrons whereas the atom of an element Y contains 11 protons, 11 electrons, and 12 neutrons.(a) What type of ion will be formed by an atom of element X ? Write the symbol of the ion formed.(b) What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from X?(c) What type of ion will be formed by an atom of element Y ? Write the symbol of the ion formed.(d) What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from Y?(e) What is the atomic mass of (i) X, and (ii) Y?(f) What could the elements X and Y be?
- (a) What is meant by (i) atomic number, and (ii) mass number, of an element? Explain with the help of an example.(b) What is the relation between the atomic number and mass number of an element?(c) If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain?
- An atom of an element X may be written as 94X.(a) What does the figure 9 indicate?(b) What does the figure 4 indicate?(c) What is the number of protons in atom X?(d) What is the number of neutrons in atom X?(e) What is the number of electrons in atom X?(f) How many electrons are there in the outermost shell of an atom of element X?(g) Write the symbol of ion formed by an atom of element X.
- The atomic number of an element X is 16.(a) Write down the electronic configuration of X.(b) What will be the valency of X ?
- An atom of element E contains 3 protons, 3 electrons and 4 neutrons :(a) What is its atomic number?(b) What is its mass number?(c) Write the electronic configuration of the element E.(d) State whether element E is a metal or non-metal. Why?(e) What type of ion, cation or anion, will be formed by an atom of element E? Why?(f) Write the symbol of the ion formed by an atom of element E.(g) What could element X be?
- The composition of two atomic particles is given below : X YProtons : 8 8Neutrons : 8 9Electrons : 8 8(i) What is the mass number of X ?(ii) What is the mass number of Y ?(iii) What is the relation between X and Y ?(iv) Which element/elements do they represent ?
- ββAtomic number of an element is considered to be a more appropriate parameter than its atomic mass for a chemist.ββ Take the example of the element X (atomic number 13) to justify this statement.
- Calculate the number of aluminium ions present in 0.051 g of aluminium oxide. (Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u)
- (a) Describe the Rutherford's model of an atom. State one drawback of Rutherford's model of the atom.(b) The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
- The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively.(a) Calculate the average atomic mass of elements X and Z. (b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y? (c) Which law of classification of elements is illustrated by this example? (d) What could the elements X, Y and Z be? (e) Give another example of a set of elements which can be classified according to this law.
- (a) Define atomic mass unit. What is its symbol?(b) Define atomic mass of an element.(c) What is meant by saying that 'the atomic mass of oxygen is 16'?
Kickstart Your Career
Get certified by completing the course
Get Started