yo pls help All organisms have a barrier that separates their internal environment from the outside world. Which of the following organ systems forms a barrier between the internal and external environments for humans? A. integumentary system B. circulatory system C. nervous system D. excretory system

Silica, sio2, is formed on silicon as an electrically insulating layer for microelectronic devices. silica is formed when silicon is exposed to o2 gas at an elevated temperature. at 900˚c, it takes 90 minutes for the oxygen to diffuse from the surface to form a 0.06 micron (0.06 x 10-6 m) thick layer of sio2 on

If 3.00 g of titanium metal is reacted with 6.00 g of chlorine gas, cl2, to form 7.7 g of titanium (iv) chloride in a combination reaction, what is the percent yield of the product?

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes