2 atome nitrogen , 1 is correct
Answer: True.
Explanation.
The group 7A is actually named group 17.
That group is the halogens: F, Cl, Br, I, At, and Ts (Ts is one of the last elements discovered).
Those elements have 7 valence electrons (notice that it is the same number as the second digit in 17).
The atoms with 7 valence electrons will "easily" gain one electron to get the configuration of the next noble gas (8 valence electrons). That is why these elements gain electrons to form ions.
When atoms gain electrons form anions (negative ions). For example: F(-), Cl(-), Br(-), I(-).
18 D
19 B
20 D
21 Anabolic steroid abuse can lead to kidney and liver failure, enlarged heart or high blood pressure and changes in blood cholesterol.
1.
The balanced chemical reaction is:
N2 +3 I2 = 2NI3
We are given the amount of product formed.
This will be the starting point of our calculations.
3.58 g NI3 ( 1 mol NI3 / 394.71 g NI3 ) ( 3
mol I2 / 2 mol NI3 ) = 0.014 mol I2.
Thus, 0.014 mol of I2 is needed to form the
given amount of NI3.
I think number one is c not sure or not number 2 is C AND NUMBER 3 IS 1 Go with sliding friction number 2 go with rolling friction number 3 is static friction and 4 is force
