nguyenhue371963

square root of x^6

How many positive factors does 2020 have?

In how many ways can a committee of 1 men and 3 women can be formed from a group of 3 men and 4 women?

For transition elements, the number of valence electron is the same as _______.

calculate : 

cos(15).cos(30).cos(45)

A                       can be defined as whatever people use to create services and goods.

2.Which of the following is used in pencils?

After the World Wars, many Jewish people migrated to which nearly established county because of long, traditional links to the religion? 

A. Isreal

B. Jordan

C. Lebanon 

D. Syria 

which statement about nitrous acid and nitric acid is correct?

A) They are both weak acids

B)They are both strong acids

C)They both have one ionizable proton

D)Nitrous acid has the formula HNO3

E)Nitric acid has the formula HNO2

What is the molar mass of calcium?

What principle states about the fundamental limitation that, for a particle as small as the electron, one cannot know exactly where it is and at the same time know its energy how it is moving?

Where is Kalingrad?

X+5=10 evaluate value of x

45×13+3+6=? 

x +15=5x+10

Calculate value of x

find the value of x.
2x + 2y = 10 and 3y + 5x = 9

7×5+7×9=? Calculate 

8×5-4×6+78=?

7×2×4×8 calculate 

11×5=? Calculate 

What is ALU

4.The gas usually filled in the electric bulb is?

A. nitrogen B. hydrogen C. carbon dioxide D. oxygen

What is the only gas in Group VIA in the periodic table

What is the most abundant element in the atmosphere?

The _______ of the atom describes the atom as having a nucleus at the center around which electrons move?

What are the main energy levels where the valence electrons belong called?

What is made of gas atoms that have been cooled to near absolute zero at which temperature the atoms slow down, combine and forms a single entity known called a superatom?

 Who coined the term “plasma” in 1928?

Who first identified plasma in 1879?

 The process of gaining or losing an electron results to the formation of a charged atom or molecule called

 The fifth state of matter, the BEC (Bose-Einstein condensate) was first created in what year?

What element is used in advertising signs?

Who first predicted the Bose-Einstein condensate (BEC) in 1924?

Aside from liquid, gas and solid, there are two other states of matter.

Who discovered the uncertainty principle?

What is the second most abundant element in the atmosphere?

What mass of H2SO4 is contained in 25g of 15% w/w solution? (Relative atomic mass are H=1amu , S=32amu, O=16amu)

h2s04(đặc nóng )+Fe--->   ..............

tính khối lượng của 0.5 mol h2so4