9th Class General Science Chapter 4 Test04. Structure of Atom

Q1. Multiple choice questions (Attempt all · 8 × 1 = 8)

1. The neutral atoms of all of the isotopes of the same element have
   1. Different number of protons
   2. Equal numbers of neutrons
   3. The same number of electrons
   4. The same mass numbers
2. How many neutrons are there in an atom of potassium
   1. 19
   2. 20
   3. 39
   4. 58
3. What does atomic number of an element indicate indicates?
   1. Neutron plus number of protons in the nucleus
   2. Electron in the nucleus
   3. Neutron in the nucleus
   4. Proton in the nucleus
4. The space surrounding the nucleus is called the
   1. Electron cloud
   2. Ionic field
   3. Nucleus field
   4. Proton cloud
5. Which of the following determines the atomic number of an atom?
   1. Number of electrons
   2. Number of protons
   3. Number of electrons and protons
   4. Number of protons and neutrons
6. An atom becomes negatively charged by.
   1. Gaining an electron
   2. Losing an electron
   3. Losing a proton
   4. Gaining a neutron
7. Which of the following statements you think is wrong regarding a particle scattering effect?
   1. A particles mostly move through the gold foil having zero deflection
   2. A small fraction are deflected
   3. One in twenty thousand turns 180°
   4. The thickness of the gold foil is about 100μm
8. Rutherford carried out experiments in which a beam of alpha particles was directed at a thin piece of metal foil. from these experiments he concluded that:
   1. Electrons are massive particles
   2. The positively charged parts of atoms are moving about with a velocity approaching the speed of light
   3. The positively charged parts of atoms are extremely small and extremely heavy particles
   4. The diameter of an electron is approximately equal to that of the nucleus