2 A chain reaction occurs when: A Electrons collide B Neutrons cause further fissions C Protons combine D Energy is lost
3 Fusion requires very high: A Pressure only B Temperature only C Temperature and pressure D Density only
8 Atoms of the same element with different mass numbers are called: A Isobars B Isotones C Isotopes D Nuclides
9 Half-life of a radioactive substance is the time required for: A All atoms to decay B Half of the atoms to decay C One atom to decay D Radiation to stop
10 Which observation supports the existence of dark matter? A Planet motion B Galaxy rotation curves C Tides D Seasons
14 A scientific theory is falsifiable if it can be: A Proved true B Observed directly C Tested and proven false D Mathematically solved
15 Falsifiability is related to: A Mathematics B Scientific theories C Engineering design D Technology
16 Dark matter is called dark because it: A Is black in color B Does not emit light C Is far away D Is very hot
18 The relation E = mc² shows that: A Mass is constant B Energy is conserved C Mass can be converted into energy D Energy depends on velocity
19 Which device is used to detect radiation? A Thermometer B Galvanometer C Geiger-Muller counter D Voltmeter
20 Ionizing radiations mainly cause damage by: A Heating matter B Ionizing atoms C Reflecting light D Producing sound