What is changed when matter undergoes a physical change?

26. of of (aq) by (aq) is . if 50.00 ml of 1.05 m is to 25.00 ml of 1.86 m ,at be? ( no is toina of aof) , h.. (p. ). . .

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it