cho 7,35 gam hỗn hợp gồm kim loại kiềm A và Kali tác dụng với nước . để trung hòa dung dịch thu được cần 0,25 mol HCl vậy A là ?

Measuring which physical property is most likely to produce the most precise results when trying to identify a substance

Water molecules have a strong attraction to each other because of hydrogen bonding, allowing water to move against gravity up a plant's stem through capillary action. true false

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size