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.
Answer:
<h2>1.686 × 10²⁴ atoms</h2>
Explanation:
The number of silicon atoms can be found by using the formula
<h3>N = n × L</h3>
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 2.8 × 6.02 × 10²³
We have the final answer as
<h3>1.686 × 10²⁴ silicon atoms</h3>
Hope this helps you
Test tube of ammonium chloride (NH4Cl) being heated over a bunsen burner flame. Ammonium chloride decomposes readily when heated, but condenses in the cooler area at the top of the test tube. This is a reversible reaction, where the ammonium chloride decomposes into the gases ammonia (NH3) and hydrogen chloride (HCl).
When a plant goes through photosynthesis, it uses light energy and converts it into chemical energy
Evaporation is when a liquid turns into a gas, while sublimation is when a solid turns into a gas. Both involve absorbing energy to break apart the bonds of the substance. On the other hand, an example of sublimation is dry ice.
