A.134.5

B.0.03

C.36.93

D.1.47

正确答案：36.93

6、For an 8.0-MeV α particle scattering from a gold atom（Z = 79 ） of radius 0.135 nm， the largest scattering angle， θ is ？（）

A.

B.

C.

D.

正确答案：

7、According to structure of atom electron should fall in（）？

A.nucleus

B.outer environment

C.shell

D.space

正确答案：nucleus

8、Which of the following is not a valid conclusion from Rutherford’s alpha particle scattering experiment？（）

A.The atom is mainly empty space

B.The nucleus must be positively charged

C.The nucleus must be very small compared to the atom

D.The mass of the atom is mostly concentrated in the nucleus

正确答案：The nucleus must be positively charged

9、A 5.0-MeV alpha particle approaches a gold nucleus with an impact parameter of 2.6×10-13 m.Through what angle will it be scattered？（）

A.10°

B.Plasma physics

C.Astrophysics

D.Environment

正确答案：10°

10、What fraction of a beam of 7.7-MeV alpha particles incident upon a gold foil 3.0×10-7 m thick is scattered by less than 1°？（）

A.1.35

B.0.67

C.0.05

D.0.84

正确答案：0.84

第三章单元测试

1、When an electron jumps from its orbit to another orbit， energy is（）.

A.absorbed

B.emitted

C.no effect

D.both

正确答案：both

2、What determines the difference in energy between two energy levels？（）

A.distance between the two energy levels

B.number of electrons in the energy levels

C.distance from the nucleus

D.number of valence electrons

正确答案：distance between the two energy levels

3、According to Bohr model of hydrogen atom， the radius of stationary obit characterized by the principal quantum number n is proportional（）