chemistry for health sciences

Correct Answer: D

Rationale: The correct answer is D because when alpha particles are beamed at a thin metal foil, some pass directly through due to their small size and high energy (option A), while others are reflected by direct contact with nuclei in the metal foil (option C). This is based on the Rutherford scattering experiment which showed that alpha particles can be deflected by the positive nuclei in the metal foil. Option B is incorrect as alpha particles are not diverted by attraction to electrons in the foil. Option D combines the correct explanations for the behavior of alpha particles when beamed at thin metal foil.

Correct Answer: B

Rationale: The correct answer is B: $2.20 /gal. To convert the price of London petrol given in British pounds to dollars per gallon, we first need to convert the price from pounds to dollars using the current exchange rate. Then, we convert the price per liter to price per gallon by multiplying by the conversion factor (1 gal = 3.7854 L). The conversion results in $2.20 /gal. Choice A ($4.46 /gal) is incorrect because it is not the correct conversion of the given price. Choice C ($9.05 /gal) is incorrect as it is too high based on the correct conversion. Choice D ($1.58 /gal) is incorrect as it does not accurately reflect the conversion from pounds to dollars and liters to gallons.

Correct Answer: B

Rationale: The correct answer is B: Alpha particles greatly deflected by the metal foil. In the Thomson model, the atom was thought to be a uniform, positively charged sphere. If this model had been correct, alpha particles would have passed through the foil with little or no deflection. However, Rutherford observed significant deflections, indicating a concentrated positive charge at the center (nucleus). This aligns with the concept of the Rutherford model of the atom. Choices A, C, and D are incorrect because they do not correspond to the experimental observations made by Rutherford.

Correct Answer: D

Rationale: The correct answer is D because when alpha particles are beamed at a thin metal foil, some pass directly through due to their small size and high energy (option A), while others are reflected by direct contact with nuclei in the metal foil (option C). This is based on the Rutherford scattering experiment which showed that alpha particles can be deflected by the positive nuclei in the metal foil. Option B is incorrect as alpha particles are not diverted by attraction to electrons in the foil. Option D combines the correct explanations for the behavior of alpha particles when beamed at thin metal foil.

Correct Answer: C

Rationale: To calculate the mass of water in the water bed, first convert all dimensions to the same unit (centimeters). The dimensions are: 55 m = 5500 cm 53 dm = 530 cm 235 cm Volume = length x width x height = 5500 cm x 530 cm x 235 cm = 69,335,500 cm� Density of water = 1 g/cm� Mass = Volume x Density = 69,335,500 cm� x 1 g/cm� = 69,335,500 g = 6.93 x 10^7 g Therefore, the correct answer is C: 1.52 x 10^5 g. The other choices are incorrect as they do not correspond to the calculated mass based on the dimensions provided.