11. aflati masa unei foi de tabla cu forma de paralelipiped cu lungimea de 4m latimea de 3m si grosimea 5mm, stiind ca densitatea este 7800kg/m3

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.