Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
Polyester is a condensation polymer of dicarboxylic acid and diol.
Example : Polethylene terphthalate is polymer of ethylene glycol and tere phthallic acid.
When a strong acid like HCl or a strong base like NaOH comes in contact with polyester (like spilled on slacks) it causes hydrolysis of polyester and it get converted back to dicarboxylic and diol(the monomers).
the general reaction will be
RCOOR' ---> RCOOH + R'OH
Thus slacks will get teared.
Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat. If there is a temperature difference between two systems heat will always find a way to transfer from the higher to lower system.
