Answer is (4) - Pb.
According to the reactivity series of elements
- the elements which are above the hydrogen are more reactive than hydrogen.
- the elements which are below the hydrogen are less reactive than hydrogen.
Among the given choices, only Pb is placed above the hydrogen in the reactivity series and rest are below the hydrogen.
Hence, Pb is more active than hydrogen.
What kind of control like scientific?
Answer:
Introduction to Basic Microscopy. Microscopes are specialized optical instruments designed to produce magnified visual or photographic (including digital) images of objects or specimens that are too small to be seen with the naked eye.
Microscope are the important tools which are used by scientist. For example, in material science, medicine, mineralogy and microbiology.
Light microscope is able to send light. Light is being focused in a tight breath whereby that light passes through a sample which later it is able to create an image. This image passes to different lenses which magnifies it until it reaches the camera.
There are different types of microscope for example, Compound light microscope, Simple light microscope, and monocular microscope.
In simple light microscope only one lens which which is being used to magnify an object and it is not able to reach to a higher magnification.
In compound light microscope it uses two lenses to produce image. For example eyepiece lens and objective lens.
Explanation:
The sand provides a rough surface on top of the ice for the cars' tires to grip onto. It provides more friction. Salt melts the ice and often provides more friction (the disadvantage is that it eats concrete!).
