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changes in science
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| Question | Answer |
|---|---|
| How can you identify a physical change? | You can identify a physical change if you can still identify the substance. If it retains its original identity, it is a physical change. |
| Physical change or chemical? #1 | Butter melting in a pan is Physical |
| Physical change or chemical? #2 | Salt dissolves in water Physical |
| Physical change or chemical? #3 | Paper is shredded is physical |
| Physical change or chemical? | Grass cut Physical |
| Physical change or chemical? | A candle is burned is chemical |
| Physical change or chemical? | Fireworks explode is chemical |
| Physical change or chemical? | An apple turns brown is chemical |
| In the equation Na + O2 → Na2O, what is/are the product(s)? | The compound Na2O is the only product in the reaction. |
| Why do nuclear changes require more energy than chemical changes? | To change the nucleus, you must overcome more attractive forces than in a chemical change. Nuclear changes affect the protons in the nucleus; chemical changes affect the electrons surrounding the nucleus. |