Ask someone to be your friend. If they dont want to be your friend then ask someone else.
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.
Diamonds are composed of carbon in a tetrahedral lattice. That is option C.
<h3>What is a diamond?</h3>
A diamond of defined as an allotrope or one of the major forms of the element, carbon in nature.
These carbon atoms are arranged within the diamond in a face centered cubic tetrahedral lattice shape.
Therefore, Diamonds are composed of carbon in a tetrahedral lattice.
Learn more about carbon here:
brainly.com/question/19083306
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Answer:
1 g
Explanation:
The half-life of Am-242 (16 h) is the time it takes for half of it to disappear.
We can make a table of the mass left after each half-life.

The mass remaining after 48 h is 1 g.
Answer:
there are 6 significant figures in 107.051