Bài 4: Cho 8 g SO3 tác dụng với nước tạo thành 200g dung dịch A a. Viết PTHH của phản ứng xảy ra? Xác định C% của dung dịch A?
b. Hòa tan vừa đủ m gam Fe2O3 vào dung dịch A. Tìm m?

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.

i do not get it   at all