What are the must memorizes for junior high school students?

The periodic table to memorize in junior high school has 36 names and pronunciations:

1 H; 2 heliumHE; 3 lithium li; 4 Beryllium BE; 5 boron b; 6 C2; 7 nitrogen n; 8 oxygen o; 9 fluorof; 10 neon;

11 sodium Na; 12 mg mg; 13 aluminium al; 14 silicon si; 15p；16 sulfurs; 17 chloroc cl; 18 argon; 19 potassium k; 20 calcium ca;

21 scandium sc; 22 titanium Ti; 23 vanadium v; 24 cr cr; 25 manganese mn; 26 iron Fe; 27 cobalt co. 28 nickel Ni; 29 copper cu; 30 zinc zn;

31 gallium ga; 32 germanium ge; 33 arsenic as; 34 selenium se; 35 bromobr; 36 krypton kr;

Classification of junior high school English words: week, month, season, time, country, direction;

transport, meal, rice, flour and meat, fruit, vegetable, and snack;

Drinks, relish, school supplies, colors, body parts, etc. A one-stop study abroad guide.

The math formula that must be memorized in junior high school is as follows:1. The perimeter of the diffuse and rectangular = (length + width) 2 = 2 (a + b) = (a + b) 2 2. The perimeter of the square punch ridge = side length 4 = 4a

3. The circumference of the circle = pi Diameter = d = pi radius 2 = 2 r 4. The area of the rectangle = length and width s = ab

5. The area of the square = the length of the side The length of the side = a

6. The area of the triangle = base height 2s = ah 2

7. The area of the parallelogram = the base height s = ah

8. The area of the trapezoid = (upper bottom + lower bottom) height 2s = (a + b) h 2 9. diameter = radius 2d = 2r

10. Radius = diameter 2r=d 2

Ten. 1. The area of the circle = pi radius radius.

Ten. 2. The area of the triangle = the height of the base 2s = a h 2 ten. 3. The area of the square = the length of the side The length of the side = a a ten. Fourth, the area of the rectangle = length and width s = a b

Ten. 5. The area of the parallelogram = the base height s = a h ten. 6. The area of the trapezoid = (upper bottom + lower bottom) height 2s = (a + b) h 2 ten. 7. Sum of internal angles: The sum of the internal angles of the triangle = 180 degrees.

Ten. 8. The volume of the cuboid = length, width, height, v=abc ten. 9. The volume of the cuboid (or cube) = the base area of the height v = sh two. 10. The volume of the cube = edge length edge length edge length v=aaa

Junior high school students must memorize element: hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, argon, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium.

The periodic table of chemical elements is a list of chemical elements sorted from smallest to largest according to the number of nuclear charges. The list is generally rectangular in shape, with spaces in the period of some elements, so that elements with similar characteristics are grouped in the same group, such as alkali metal elements, alkaline earth metals, halogen elements, noble gases, non-metals, transition elements, etc.

This makes the periodic table form an elemental division and is divided into seven main families, seven secondary families, and the family is called Hongbi, and the 0 family. Because of its ability to accurately ** the properties of various elements and the relationships between them, the periodic table is widely used in chemistry and other scientific fields as a useful framework for analyzing chemical behavior.

The words that must be memorized in junior high school are as follows:

1. brown: English words, adjectives, nouns, transitive verbs, intransitive verbs.

When used as a transitive verb, it means "to make brown". When used as an intransitive verb, it means "to turn brown". When used as an adjective, it means "brown, brown; sun-tanned". When used as a noun, it means "brown, brown".

2. snake: snake is an English word, noun, transitive verb, intransitive verb, translated as "snake" when used as a noun; insidious people". When used as a transitive verb, it is translated as "to pull (timber and other deficits); Roundabout forward".

When used as an intransitive verb, it is translated as "to move forward in a roundabout way".

3. Giraffe: English word, referring to giraffe.

Camelopardalis; inclined shaft hoisting minecart; Ground dumping (mining) truck device; Multi-layer buckets, aerial work lifting tables.

4. cousin: cousin is an English word, noun, which means "cousins and sisters" when used as a noun; cousins and sisters".

5. engineer: English words, nouns, transitive verbs, intransitive verbs, when used as nouns, it means "engineer; Sapper; train driver", when used as a transitive verb, means "design"; Mastermind; to deal wisely", when used as an intransitive verb, means "to design; Build".