Someone is handsome if they appear attractive, healthy and strong. Handsome is a term most commonly applied to men, but can also be used to describe animals and women.
When you are happy, you feel good and smile a lot. Being happy is the nicest way to be. People are happy when things go the way they want, when people are nice to them or when they are having fun. The person in the picture is happy.
Something is hard if it is solid to touch, and you cannot squash or bend it. Stones are very hard. The opposite of hard is soft.
You are healthy if you are in a state of good health. Healthy people and animals are in good condition, and are not sick or injured. Healthy food is food that is good for you, and helps you to stay healthy.
Something is heavy if it weighs a lot and is difficult to carry. You need to be strong to carry something that is heavy. The woman in the picture is carrying some heavy boxes.