They have seven electrons in their valence shell, so halogens are very reactive.
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Answer:
H2O2
Explanation:
2 hydrogen, 2 oxygen wikipedia it
C. A magnet causing a metal object to move
Answer:
C. Extinctions have occurred many times throughout the Earth's history.
Explanation:
1) Body tube (Head): The body tube connects the eyepiece to the objective lenses. Arm: The arm connects the body tube to the base of the microscope. Coarse adjustment: Brings the specimen into general focus. Fine adjustment: Fine tunes the focus and increases the detail of the specimen.
2)Microscopes are made up of lenses for magnification, each with their own magnification powers. Depending on the type of lens, it will magnify the specimen according to its focal strength.
3)In simple magnification, light from an object passes through a biconvex lens and is bent (refracted) towards your eye. ... The eyepiece lens usually magnifies 10x, and a typical objective lens magnifies 40x. (Microscopes usually come with a set of objective lenses that can be interchanged to vary the magnification.)
