Answer:
A. a new substance is being produced.
Explanation:
The bubbles most likely indicates that a new substance is being produced by this reaction. In essence, we describe this sort of change as chemical change.
In a chemical change, new substances are usually produced. They are accompanied by the evolution or absorption of energy.
The reaction of Zinc with a strong acid to produce bubbles on the surface of the metal indicates a chemical change and the formation of a new kind of substance.
Take for example, let zinc reacts with hydrocholoric acid, HCl;
Zn + 2HCl → ZnCl₂ + H₂
Since Zn is higher than Hydrogen in the activity series, it will displace it from HCl and liberate hydrogen gas as a product. This will cause the bubbles observed in the reaction.
This is a chemical change and new products have been formed.
B and D are wrong because they are both physical changes.
C is wrong because no information about such is provided by the problem statement.
So, when a piece of zinc metal combines with a strong acid, a new kind of substance is produced.
0,15 moles of NaOH-------in------------1000ml
x moles of NaOH------------in--------100ml
x = 0,015 moles of NaOH
final volume = 150ml
0,015 moles of NaOH---in-------150ml
x moles of NaOH--------------in-----1000ml
x = 0,1 moles of NaOH
answer: 0,1mol/dm³ (molarity)
Answer:
+3
Explanation:
Sorry, I don't have one for now. I remember answering this a while ago, but I don't remember the exact reason why it's 3+.
Explanation:
In a magnetic field, the radius of the charged particle is as follows.
r = 
where, m = mass, v = velocity
q = charge, B = magnetic field
Therefore, q will be calculated as follows.
q = 
= 
= 
= 
= +2e
Thus, we can conclude that the charge of the ionized atom is +2e.
I can’t see what image you have to refer too but India is now part of the rest of Asia due to continental plates running into eachother.
