How many atoms are in 1500ml of O2

Why do cells appear different in distilled water than they do in 10% salt water?

20 pts ‼️ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraft’s weight the greatest?

Two nails have identical sizes and shapes. in one nail, 20 percent of the domains are lined up. in the other nail, 80 percent of the domains are lined up. which has stronger magnetic force? first answer gets brainliest!