Do measurement experiments to experience life

After you have learned to measure the mass of an object with a balance, estimate the mass of an egg and then measure it with the balance to see if your estimate is accurate. Then use the balance to weigh the mass of 10 eggs, calculate the average mass of each egg, and compare it to your estimated value.

2.

Doing an inertia experiment with a scare

Put a piece of cardboard on the mouth of a glass half full of water, then put an egg on the piece of paper, and use your hand to pop the piece of cardboard out suddenly, and the egg will fall safely into the glass.

3.

Do inertia experiment, accurate judgment

With raw and cooked eggs each one, respectively, on the table, at the same time to the same speed rotation, because the cooked egg yolks and whites are fixed, so the rotation of the smooth, while the raw egg due to inertia, wobbling, and soon stop rotating, and from this you can accurately determine the raw eggs cooked eggs.

4.

Pressure experiment, intuitive

Pinch the egg with your hand, due to the uniformity of the force on the surface of the egg, the pressure is less, the egg is difficult to pinch the egg, but if we use the same hand to pinch the two eggs, due to the small area of contact between the egg and the egg is subjected to the pressure is large, it is very easy to pinch the egg broken.

5. do the atmospheric pressure experiment, interesting

In the bottle mouth than the egg slightly smaller than the bottom of a wide-mouth bottle sand, will be soaked in alcohol cotton lit quickly into the bottle, later will be peeled cooked eggs blocked the bottle mouth, after a while, due to the role of atmospheric pressure, the cooked eggs will be swallowed by the glass bottle.

6. Do buoyancy experiments, lively and interesting

Put a raw egg into a glass of water, you can see the egg sink into the water. Then gradually to the cup into the salt, and constantly stirring, you can see the egg suspended in the water anywhere. Continue to add salt to the glass until the egg floats in the water. From this we can see three states of the egg in salt water.

Biology experiment:

Method of making leaf vein specimens of plants

I.

Purpose of the experiment:

1.

Learn to make leaf vein specimens

2.

Cultivate hands-on ability and interest in biology class

II.

Pharmaceuticals:

naoh (highly corrosive, use with extreme caution), na2co3, hydrogen peroxide (or bleach), dyes.

Three,

Equipment:

Beaker, electric stove, large tweezers, toothbrush, plastic plates, glass rods, small plastic buckets, absorbent paper (or grass paper)

Four,

Operating steps:

1,

Selection: Select the leaf thicker, moderate size, leaf surface flat, leaf veins are rich in the leaf (such as cinnamon leaves, linden leaves), use the leaves to make the leaf, and then use the leaf to make the leaf. leaves, linden leaves), wash with water and set aside.

2.

Making solution: Weigh 35gnaoh and 25gna2co3 into a beaker, add 1l of water to dissolve, make the solution.

3,

Heating: put the solution into the electric stove heating, nearly boiling when the leaves immersed in the solution, at this time the temperature of the electric shanghai to lower the temperature, while heating and stirring; the length of the heating time according to the leaves, you can take a piece of two or three minutes out of the observation, until the leaves become brown (or the leaf flesh has fallen off) can be.

4,

Rinsing: stop heating, use tweezers to take out the leaves, put into a small plastic bucket of water rinsing clean (generally more than two times)

5,

Brushing: put the leaves on a plastic plate, add a layer of water, the toothbrush slanting (with the level of the plane at an angle of about 45 degrees), along the veins of the leaves gently brushing clean flesh, brushing, pay attention to: only one direction brush (absolutely not back and forth brush), the toothbrush, the toothbrush, the toothbrush, the leaf pulp. When brushing, be careful: only brush in one direction (never brush back and forth), so as not to brush the leaf veins bad. Brush from the back first, brush the back and then brush the front, the main leaf veins can be knocked out at the edge of the method. Brush clean and put on absorbent paper (or straw paper) to dry.

6,

Bleaching: Use 20% hydrogen peroxide (or bleaching powder) to bleach the leaf veins.

7,

Dyeing and drawing: You can use red potion, purple potion, magenta and dyes to color the leaf veins, or you can draw on the veins.

8,

Paste and overglue: after drying, it can be glued with paper and overglued for preservation.