2024 Beijing Question 1 Single-choice Differentiating 2024_北京卷 (物理) 1. 已知钍234的半衰期是24天。1g钍234经过48天后,剩余钍234的质量为( ) A. 0gB. 0.25gC. 0.5gD. 0.75g Answer keyB ☆ SaveCan't do it, show the explanation查看原卷 →