Which of these igneous rocks cooled so quickly that crystals did not form, creating a natural glassy look?

Obsidian is produced when lava cools very quickly. The lava coo ls so quickly that no crystals can form. When people make glass they melt silica rocks like sand and quartz then cool it rapidly by placing it in water. Obsidian is produced in nature in a similar way.

$100. 125 x 0.20 = 25125 - 25 = $100

If these are the missing choices: a. to determine skin temperature, place the back of your hand against the patient's skin.b. determine body temperature by touching the patient's hands and feet.c. skin temperature will tell you very little about this patient's condition or well-being.d. the patient's skin temperature and color will likely be warm and red.my answer is: a. to determine skin temperature, place the back of your hand against the patient's skin. using the back of the hand to check for temperature rather than the palm is more effective because the back of the hand has more nerves that can feel and transmit the temperature than the palm.