Please help asap and when ur doing the answers (for example) put 1 is A .. (if u send me a link to the answers Im reporting you just write it down please) and reason I will report . Anyways here are the photos. FYI U WILL GET 20 POINTS!!

What is the density of the black hole

Start an single atom tab. observe the decay of polonium-211. after each decay, press the reset nucleus button to watch the process again. write a description of alpha decay for po-211

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?