Answer:
the newspaper one is a chemical change because the chemicals in the paper have reacted with something and turned a different color. the wax one is a physical change because it is a change in the phase of matter, which is always a physical change (still the same substance chemically)
Answer:
The number of moles: 0.25442 moles
Explanation:
One mole of Neon gas will occupy 22.4 at STP.
5.699L consists of 
= 0.25442 moles.
Explanation:
Na represents the neutral element; Sodium. Because of it's atomic number of 11, It has 11 electrons.
Na+ on the other hand represents a cation. The sodium ion has lost an electron, hence the total number of electrons it has = 10.
The K and L shells each have maximum number of electrons they can accommodate. This is given by the formular; 2n^2
K shell = 2 (1)^2 = 2 electrons
L shell = 2 (2)^2 = 8 electrons
Seeing as Na+ has 10 electrons, It completely filled the K and L shells ( 2 + 8 = 10 )
Explanation:
acid --> HCN
base --> KCN
now
another base NaOH is added
we know that
base will react with an acid
so
OH- + HCN ---> CN- + H20
we can see that
HCN is used up , so number of moles of HCN will decrease
CN- is being formed , so number of moles of CN- will increase.
A false
B false
C false
D true
E false
