Meat and other types of tough food
The outer coverings that are tough but, flexible provided protection to the land plants.
Answer:
A spade placed in the fire turns hot.
Explanation:
Trees take in carbon dioxide to build their tissues , which releases oxygen for us in the process.
The sodium hydroxide solution and vegetable oil underwent a chemical change.
<h3><u>Explanation:</u></h3>
The reaction between a base and a fat or fatty acid is called as saponification reaction. Here the base dissociates into the cation and hydroxyl ion. The hydrogen from the fatty acid of the oil reacts with the hydroxyl ion to form water which is basically the neutralization reaction. This cation now reacts with the rest of the fatty acid to form a bipolar molecule which is the soap. During the reaction, the solution becomes cloudy but with time, it again goes back to solution. The cloudyness appears because oil isn't soluble in water based solutions and the base is actually made solution in water.
Here the sodium hydroxide reacts with oil to form water and the soap molecule which is a chemical change.
