Plss
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a substance undergoes a change.
which statement indicates that the change was a physical change?
heat energy was given off.
the substance changed color.
the molecules of the substance changed.
the substance changed shape.

Option (d) is the correct answer.

Explanation:

A change that does not bring any difference in chemical composition of a substance is known as a physical change.

For example, shape, size, density, mass etc are all physical changes.

Change in color is not necessarily a physical change because sometimes color of a substance changes due to chemical reaction.

For example, during rusting color of iron changes.

Whereas a change that brings difference in chemical composition of a substance is known as a chemical change.

For example, reactivity, release or absorption of energy, toxicity etc are all chemical changes.

Thus, we can conclude that the statement substance changed shape was a physical change.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.