Download App

Structure of the Atom — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceStructure of the Atom2 Marks
Question
The composition of two atomic particles is given below:
 
X
Y
Protons
$8$
$8$
Neutrons
$8$
$9$
Electrons
$8$
$8$
  1. What is the mass number of $X$?
  2. What is the mass number of $Y$?
  3. What is the relation between $X$ and $Y$?
  4. Which element/ elements do they represent?
✓

Answer

  1. Mass number of $X = 8 + 8 = 16$
  2. Mass number of $Y = 8 + 9 = 17$
  3. $X$ and $Y$ are isotopes, as they have the same number of protons but different number of neutrons.
  4. $X$ and $Y$ represent the isotopes of oxygen.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Que-Ans (Each of 2 Mark )" from Structure of the Atom→Structure of the Atom — all question types→Science STD 9 question papers→Gujarat Board STD 9 question papers→Gujarat Board question paper generator→

Similar questions

Which of the following are not compounds?
  1. Chlorine gas
  2. Potassium chloride
  3. Iron
  4. Iron sulphide
  5. Aluminium
  6. Iodine
  7. Carbon
  8. Carbon monoxide
  9. Sulphur powder
→
A body with an initial velocity x moves with a uniform acceleration y. Plot its velocity-time graph.
→
  1. What are the two ways of obtaining fish?
  2. What is the major problem faced in fish farming? How can it be overcome.
→
What is meant by the ‘molar mass’ of a substance? State the unit in which molar mass is usually expressed.
→
The cells of stratified squamous epithelium are arranged in many layers. Why?
→
Explain how, cathode rays are formed from the gas taken in the discharge tube.
→
What is the difference between ‘distance travelled’ by a body and its ‘displacement’$?$ Explain with the help of a diagram.
→
An artificial satellite is moving in a circular orbit of radius $42250\ km.$ Calculate its speed if it takes $24$ hours to revolve around the earth.
→
Define ‘formula unit’ of an ionic compound. What is the formula unit of:
  1. Sodium chloride
  2. Magnesium chloride?
→
Name two countries that are centres of megadiversity.
→