[Haichuan Teahouse] How dare they call it an easy question – can you even do it?

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In the 2021 Guangdong physics exam for the college entrance examination, there were 8 points given as a bonus right from the start – have you got them? ① Scientists have discovered a large amount of the radioactive isotope aluminum-26 in the Milky Way. Aluminum-26 has a half-life of 720,000 years, and its decay equation is ?????AⅠ → ????Mg＋Y. Which of the following statements is correct? A. Y is a helium nucleus. B. Y is a proton. C. After another 720,000 years, half of the existing aluminum-26 will have decayed. D. After another 140,000 years, all of the existing aluminum-26 will have decayed. ② In April 2021, China’s independently developed “Tianhe” core module was successfully launched and put into orbit. If the motion of this core module around the Earth can be considered as uniform circular motion, and given the gravitational constant, which of the following physical quantities can be used to calculate the mass of the Earth? A. The mass of the core module and its distance from the Earth’s center. B. The mass of the core module and its orbital period around the Earth. C. The angular velocity of the core module’s orbit around the Earth and its orbital period. D. The linear velocity of the core module’s orbit around the Earth and its distance from the Earth’s center