The answer for 21 I think is false
The correct statements are:
1. The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center.
2. The diverse proteins found in and attached to membranes perform many important functions.
5. Because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane.
The 4 properties given are physical properties, therefore the ones I'll list are also physical properties of sodium chloride.
These properties may include:
It is white in color
It is hard
It is brittle
It conducts electricity in molten or aqueous state
