The different types of microscopes are all necessary because not all experiments require the same level of magnification. For dissections low magnification is sufficient, so a dissecting microscope works very well, while for viewing single cells the 1000 fold magnification of a compound light microscope is more accurate.
Composer and performer of Old Occitan lyric poetryduring the High Middle Ages (1100–1350). Since the word troubadour is etymologically masculine, a female troubadour is usually called a trobairitz.
Answer:

Explanation:
We already know that the mass number of an atom is the sum of the number of protons and the number of neutrons.
So, the mass number of this isotope is;
Number of protons = 7
Number of neutrons = 8
Mass number = 7 + 8 = 15
Hence, the isotope is;

Answer: 4
Explanation:
4 is the only one that has to products as well as having the plus at the bottom
It's because they add to its hardness . Calcium is naturally dissolved in water