1)magnification goes by 10x (read 10 times), 100x,1000x and some goes 10,000x
2)Always focus first using lowest power possible first, switch to medium power (100x) after it's focused on low power(10x), on 100x, use the small knob to focus it more. DO NOT touch the bigger nob when in medium or high power. Switch to high power (100x) when it is focused on medium power, again focus again using the small knob on high power.
3) So it doesn't gather dust and fog up the lense? that one should be self explanatory
The Earth was first considered habitable when we discovered that it was Microbial organisms that started the process. I would go with D.
The answer is All of above
The reactive CARBONYL GROUP, contributes to the ability of aldehydes and ketones to be involved in energy reactions. Aldehydes and ketones undergo different types of reactions that lead to various products. One example of these reactions are nucloephilic reactions which lead to the production of alcohols, alkenes, diols, imine, etc.