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.
Explanation:
The driving force behind plate tectonics is convection in the mantle. Hot material near the Earth's core rises, and colder mantle rock sinks.
Answer : The complete net ionic reaction between
and
in an acid solution, can be written as :-
Explanation:
1. photosynthesis
2. Nucleus. The nucleus is the largest and most significant living organelle of the cell. ... Hence it is called brain or control centre of the cell.
3.Cytoplasm
Cells require a thick jelly-like substance that holds organelles in place inside the cell. This substance is known. Cytoplasm. Turgor pressure can help plants move.
4.Chloroplasts absorbing solar energy for cellular activities.
5.cell membrane
6.a.cell wall
b.chloroplast
c.large vacuole
Answer: OH−.
Explanation: Hydroxide, any chemical compound containing one or more groups, each comprising one atom each of oxygen and hydrogen bonded together and functioning as the negatively charged ion OH-.
