<span>Which of the following is an electronic device that measures pH?
</span><span>a. a pH meter</span>
Answer: On heating, Magnesium forms its oxide; while potassium manganate(VII) decomposes
Explanation:
Magnesium Mg, on heating forms Magnesium oxide
2Mg(s) + O2(g) --> 2MgO
Potassium permanganate KMnO4, on heating decomposes to potassium manganate K2MnO4, manganese dioxide MnO2, and Oxygen gas O2.
2KMnO4 --> K2MnO4 + MnO2 + O2
The difference in observation is that, on heating, Magnesium forms its OXIDE as product; while potassium manganate(VII) decomposes, giving OFF most of its constituents and reducing its weight.
9
Explanation:
cause 2 + 2 is equal to 9
Answer:
D. A compound can be separated into two or more elements through a chemical reaction.
Explanation:
By method of elimination, we are going t obtain the correct option.
A. A compound is made up of a single atom.
This is wrong because, a compound can contain more than one atom. An example is H2O
B. A compound is made up of many atoms that are all the same type.
This is wrong because a compound can contain atoms of different elements. An example is H2O. It contains atoms of hydrogen and oxygen.
C. A compound can be separated into two or more elements through physical processes.
This is wrong. H2O being a compound cannot be separated by ordinary physical means.
D. A compound can be separated into two or more elements through a chemical reaction.
This is the correct option.