Read the orchard notes

The orchard team noticed several changes during the week. A freshly cut apple turned brown after it was left in the air. In the compost heap, fruit scraps slowly broke down and released warmth. A metal gate developed a reddish-brown coating after weeks of rain. Rust forms when metal reacts with oxygen. Hannah also dissolved sugar in water to make a drink; the sugar seemed to disappear, but the liquid remained clear. The team knows that a chemical change makes one or more new substances. A physical change changes a substance's form or state without making a new substance. Bubbles, a lasting colour change, a temperature change, or a new smell can be clues to a chemical reaction, but one clue alone does not always prove one has happened. In a chemical reaction, bonds between atoms break and new bonds form, creating new arrangements of atoms. Atoms do not disappear.