Answer:
It is a physical change because this change is reversible and no chemical reaction occurs.
Explanation:
D. Two electrons in its first energy level; eight electrons in its second energy level; six valence electrons in its outermost energy level.
Please correct me if I'm wrong!! :)
Answer:
X 154
Check solution in explanation
Explanation:
Average atomic mass = ( mass 1× abudance) + ( mass 2× abudance)+ ( mass 3× abudance) / 100
(149×13.8)+(152×44.9) +(154×41.3)/100
2056.2 + 6824.8 + 6360.2/100
=152.412
H3O+(aq) + OH-(aq) --> 2H2O (l)
NaHCO3(s) --> NaH 2+ (aq) + CO3 2- (aq)
NaH 2+ (aq) + H2O (l) --> Na+ (aq) + H3O+ (aq)
H2O (l) + CO3 2- (aq) --> OH- (aq) + HCO3- (aq)
(I'm not completely sure if I did the third question right) I'm sorry if I got it wrong
