If you wanted to demonstrate a first class lever system to your peers which Childhood toy would you use as a basis for your demonstration and which body motion would you use as an example? A. A yo-yo and handshake
B. A see-saw , chin raise
C. A swing set , a leg kick
D. A slide, a squat

Option B.

A see saw, chin raise.

Explanation:

A lever is a machine that can rotate and consist of a beam which is pivoted to fulcrum.

There are three classes of lever, the first class lever, second class lever and third class lever. These three classes of lever are classified base on the positions of effort, fulcrum and Load.

In first class lever, fulcrum comes between the effort and load. Examples is scissors , see saw, pliers. This is because effort is applied on the one side of the fulcrum and load is on the other side. Therefore, the childhood demonstration of first class lever motion is see saw and chin raise.

In the second class lever, load come between effort and fulcrum e.g wheelbarrow, bottle opener.

In the third class lever, effort comes between fulcrum and load e.g hammer, broom.

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.