Seek junior high school 1 2 3 unit induction mainly 3 units 10

What are you asking, chemistry?

The periodic table is a very interesting thing, the big piece in the middle is used less, and the rest of the cards are left first.

The outermost electrons of the transverse element increase one by one by the outermost electrons up to 8, and in addition to HE, the outermost electrons 8 are the most stable, which are generally gaseous and are called noble gases.

The number of electrons in the outermost shell of the vertical row is the same, and the properties are basically the same, so the vertical row is also called the family, such as the seventh vertical row is called the halogen group or halogen. The special case is h, and the outermost electron is 1, but it is gaseous, not reactive metal. From top to bottom, it is generally a change of gas, liquid and solid, HG is a special case, HG is a liquid metal at room temperature, has strong volatility, reacts with oxygen to form HG2O, reacts with S to form HGS, and the general medical clinic is equipped with sulfur, the thermometer is broken, and the HG flowing out of the thermometer is treated with sulfur.

The large piece in the middle remembers the commonly used and famous ones, such as MN, AU, AG, etc.

There are commonly used compounds, which will use valence, maybe you haven't learned, this has to be memorized, we will give us a smooth talk: monovalent potassium K, sodium Na, chlorine Cl, hydrogen H, silver AG, divalent oxygen O, calcium Ca, barium BA, magnesium MG, zinc ZN, ditrifer Fe, ditetracarbon C, 246 sulfur S are complete!

Chemistry also has a phenomenon of detachment from science, which needs to be memorized, and there are many things that need to be memorized, if you want to learn it well, you need to put in some effort, of course, you have to work hard to learn any subject well.

I said that it would be best to find a teacher to tutor you. After all, the teacher's explanation has been summarized many times.

1) a, Europe b, Asia c, Africa.

2) e, Black Sea f, Mediterranean.

3) The Ural Mountains, the Ural River, the Greater Caucasus Mountains.

Turkish Strait Suez Canal.

3 (x 2) (x 1) 1 Solve a one-dimensional inequality and express the solution set on the number line

3x+6-x+1<1

2x<-6

x<-3

3x+6-x+1-1<0

2x+6<0

x<-3

Find -3 on the x-axis, draw a hollow circle, and draw the line to the left.

Both sides of the equation are multiplied by 4 at the same time

x-2=3 solution: x=5

1c 3b

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Select C for the first question and choose A for the third question