Writing component page 69 of isn How can you tell if a chemical change has occurred?

Formation of a new substance Page 70 of ISN

Write the signs of a chemical change and the senses you might use to detect it. (skip 4 lines) 2. What sense of observation should never be used in a chemistry laboratory?

Glue chart on the bottom of page 70 of ISN

Burning candle https://www.youtube.com/watch?v=IrR2u4_8LLg

Melting ice cube https://www.youtube.com/watch?v=FYgiZ7KzgDk

Rusting nail https://www.youtube.com/watch?v=5RUFe9eheQ0

Crushing a piece of chalk https://www.youtube.com/watch?v=HeXsBpw_SnQ

Formation of a new substance lab Question: what signs of a chemical reaction can be observed when different substances are combined? Hypothesis: If then

Hypothesis: If the different substances are combined then I will see different chemical reactions Independent variable: different substances that are being mixed together. Dependent variable: the chemical reactions such as a color change, temperature change, production of light, gas or precipitate.

Formation of a new substance continued We… formulated a question Wrote a hypothesis Identified the variables Gathered materials Wrote our procedure Gathered our data So what’s next?

Analyze data Now that we have collected data, we need to see what the data tells us. This is called analyzing data. You will answer the following questions in your ISN to help you better understand your data. (page 76-77 of ISN) REMEMBER THIS IS YOUR TEST!!!! NO TALKING!!!! Directions: Answer in complete sentences.

questions Describe exactly what you observed when a combination of substances resulted in a color change. What were the initial colors, what was the final color, and did the color change occur quickly or slowly? Describe exactly what you observed when a combination of substances resulted in a temperature change. Was the temperature change an increase or decrease? Was the temperature change easy to detect? Describe exactly what you observed when a combination of substances resulted in production of a gas. What is your evidence that a gas was produced? Why is production of a gas a good indicator that a new substance formed? Describe exactly what you observed when a combination of substances resulted in the formation of a precipitate. Why is the formation of a precipitate a good indicator that a new substance formed?

Sentence stems 1. I observed that when I combined the cabbage juice with… 2. I observed that when I combined the cabbage juice with … 3. I observed that when I combined the sodium bicarbonate with …. 4. The production of gas is a good indicator that a new substance was formed because… 5. I observed that when different substances are combined such as magnesium sulfate and…

You’re still not done! What’s next?

Conclusion What can you conclude about this investigation? Page 53 will show you what your conclusion should look like.