Iron garden tools were left outside over the winter. When found, They appeared dirty with spots of reddish-brown, flaky substance. Was this a physical or chemical change? How do you know?​

Chemical change

Explanation:

The reddish-brown substance is rust. Rust is a chemical change because rust is a different kind of matter than the iron, oxygen, and water present before the rust formed. The explosion of nitroglycerin is a chemical change because the gases produced are very different kinds of matter from the original substance.

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.

2b2t

explanation:

2b2t