Position A:_Food enters the mouth. It is broken down by chewing and grinding. Saliva is also secreted from under the tongue to help
break down the food with enzymes.
1. Is this a mechanical digestion? Chemical digestion? Both?

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.

2.38g of black copper (ii) oxide is completely reduced by hydrogen to give copper and water. what are the masses of copper and water formed? ?