Answer:
Here
Explanation:
Chemists need the mole concept to bridge the gap between the microscopic world of atoms to the macroscopic world of humans. As you know, the molecular level consists of particles that are invisible to us.
Answer:
A_____PENCIL______ consists of a mixture of graphite powder (a form of carbon) and clay that is baked and hardened and encased in wood or paper. a. silverpoint b. pencil c. charcoal d. chalk e. paste
Explanation:
A pencil is a writing material, where the graphite is what gives the black color to the writing stroke.
Answer:N
2
+ 3
H
2
-----> 2N
H
3
Explanation:
N
2
+
H
2
-----> N
H
3
Let us balance this equation by counting the number of atoms on both sides of the arrow.
N
2
+
H
2
-----> N
H
3
N=2 , H=2 N=1, H=3
To balance the number of N atom on Right Hand Side (RHS) , I will add one molecule of N
H
3
on RHS
N
2
+
H
2
-----> 2N
H
3
N=2 , H=2 N=2 , H= 6
To balance the number of H atoms on Left Hand Side (LHS) , I will add two molecules of
H
2
on LHS
N
2
+ 3
H
2
-----> 2N
H
3
N=2 , H=6 N=2 , H= 6
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Answer : The amount of heat needed is, 1188 J
Explanation :
Formula used :

where,
q = heat needed = ?
m = mass of copper = 55 g
c = specific heat capacity of copper = 
= initial temperature = 
= final temperature = 
Now put all the given values in the above formula, we get:


Thus, the amount of heat needed is, 1188 J
Answer:
answer A has four valence electrons
Explanation:
The outer shell has 4 electrons, which are considered the valence electrons