Did a New Substance Form?
Aligned to 5-PS1-4 — Next Generation Science Standards.
What this lesson teaches
Sometimes mixing two things just blends them, but sometimes it makes a brand-new substance with new properties. Clues like bubbling, a color change, heat, or a solid appearing tell you something new was created.
Worked examples
Example 1
Stir baking soda into vinegar and it fizzes fast, making bubbles of a new gas that wasn't in either one before. That fizzing is your clue that a new substance formed.
Example 2
Steel wool left out in damp air turns to orange rust and actually gets heavier, because oxygen from the air joined it.
Example 3
Not every change makes something new. Dissolving sugar in water looks dramatic, but boil the water off and the sugar is back, unchanged.
Practice questions
- Mix salt and pepper, then mix baking soda and vinegar. Which one made something new? How do you know?
- Watch for four clues (bubbles, color change, heat, new solid) while mixing safe kitchen materials.
- Explain why bubbling can be evidence that a new substance was made.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
¿Se Formó una Sustancia Nueva?
A veces mezclar dos cosas solo las combina, pero a veces crea una sustancia totalmente nueva con propiedades nuevas. Pistas como burbujas, un cambio de color, calor o la aparición de un sólido te dicen que se creó algo nuevo.
Ejemplo 1: Revuelve bicarbonato en vinagre y burbujea rápido, formando burbujas de un gas nuevo que no estaba en ninguno de los dos antes. Ese burbujeo es tu pista de que se formó una sustancia nueva.
Ejemplo 2: La fibra de acero dejada en aire húmedo se vuelve óxido naranja y de hecho se hace más pesada, porque el oxígeno del aire se unió a ella.
Ejemplo 3: No todo cambio crea algo nuevo. Disolver azúcar en agua se ve dramático, pero evapora el agua y el azúcar regresa, sin cambios.
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