Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
<span>Following is the match the mineral categories to their best descriptions:
a) </span>sulfide mineral: <span>Contain sulfur plus a metallic element
b) </span>sulfate mineral: <span>Compounds that have a sulfur atom surrounded by four oxygen atoms
c) </span>halide minerals: Contain elements like fluorine, bromine, iodine, or chlorine combined with metals. S<span>table salt is an example of this type of mineral
</span>d) carbonate mineral: Compounds made up of a carbon atom that is bordered by three oxygen atoms.
Answer:
1) the product may be contaminated by the solvent
2) side reactions may yield unwanted products
3) some reactants may be present in the product if the reaction was incomplete
Explanation:
It is common in chemistry to pass reaction products through purification processes. This is done for a number of reasons.
First of all, some solvents molecules may be attached to the reaction product. These solvent particles must be separated in order to obtain a pure product.
Secondly, some side reactions also yield products that are isolated along with the desired products and these must be separated accordingly.
Finally, some chemical reactions do not go on to completion. This implies that some reactants may still be isolated alongside the product at the end of the reaction.
Answer:
B. flourine
Flourine is the 9th element in the periodic table
