6. Lines on an absorbtion spectra are produced when electrons drop down from excited energy levels
False
True
7. What is the bond angle in a molecule with a tetrahedral shape?
109 degrees
120 degrees
180 degrees
8. What is the bond angle in a molecule with a triangular planar shape?
180 degrees
120 degrees
109 degrees
9. The half-life of carbon-14 is 5730 years. How long will it take for the sample's count rate to decrease from 160 counts per minute to 40 counts per minute?
17190 years
11460 years
5730 years
10. In group 2 elements, melting point increases down the group
False
True
11. In the ionisation area of a mass spectrometer, the sample is 'bombarded' with electrons so that...
cations are formed
all of the molecules have the same kinetic energy
anions are formed
12. What is an isotope?
atom with different number of protons, different number of neutrons
atom with same number of protons, different number of neutrons
atom with same number of protons, same number of neutrons
atom with different number of protons, same number of neutrons
13. In group 2 elements, thermal stability increases down the group