Answer:
Group 18th
Explanation:
The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.
It benefits of the solar radiation for out planet is that it gives us heat, natural sunlight and its pollution free.The disadvantage for solar radiation is that there are also some toxic materials and hazardous products used during the manufacturing process of solar photovoltaic systems, which can indirectly affect the environment.
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The objects which cannot be observed in detail without a microscope
include the following:
<h3>What is a Microscope?</h3>
A microscope is an instrument which is used to view smaller objects such as
microbe,cells, tissues etc. This instrument is used in viewing the different
cells found in the body as they can't be seen with the eye.
The remaining options which can be seen with the eyes don't require
the use of microscopes.
Read more about Microscope here brainly.com/question/25268499
Answer: 40.1%
Explanation: The mass of calcium in this compound is equal to 40.1 grams because there's one atom of calcium present and calcium has an atomic mass of 40.1 . The molar mass of the compound is 100.1 grams. Using the handy equation above, we get: Mass percent = 40.1 g Ca⁄100.1 g CaCO3 × 100% = 40.1% Ca.
Answer:
The Sandmeyer reaction is a chemical reaction used to synthesize aryl halides from aryl diazonium salts using copper salts as reagents or catalysts. It is an example of a radical-nucleophilic aromatic substitution.