B I think, it has layers that protects the cells nucleus
Density=mass/volume
density=2/8
density=0.25g/ml
5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
Answer:
A)
,
, 
A = 1.5×
, A = 1.9×
, A=1.5×
B) 4.469
Explanation:
From Arrhenius equation

where; K = Rate of constant
A = Pre exponetial factor
= Activation Energy
R = Universal constant
T = Temperature in Kelvin
Given parameters:




taking logarithm on both sides of the equation we have;

since we have the rate of two different temperature the equation can be derived as:


= 19846.04×7.544×
= 1.497
=
= 4.469
It is diffistion because it moves from an area of high concentration to low