Atomic size gradually decreases from left to right across a period of elements.
1. Synthesis reaction
2. Decomposition reaction
3. Double replacement reaction
4. Combustion reaction
5. Single replacement reaction
The change in color from silver to gold is a chemical change.
<h3>What is a a chemical change?</h3>
A chemical change is one in which a new substance is formed. In this case, we can see from the video that zinc was added along with the sodium hydroxide solution and heated
Thus we know that a chemical change would cause an alteration in how the substance looks as a result of the alterations in the arrangement of atoms in the system. This rearrangement of atoms is what causes the chemical change to occur.
The color of the coin changed from silver to gold when the coin was placed on the hotplate. This could be regarded as a chemical change because an alloy was formed in the process.
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Yes they are a pure substance
