ScienceA force is a push or a pull

ScienceA force is a push or a pull on an object.A force changes the motion of a moving object.A force can be strong or weak, and it always has a direction.The Earth is a planet that goes around the sun in a circular orbit.The Earth has a layer of gas above its surface, which helps to support life.Atoms are the building blocks of matter.At the center of an atom is its nucleus, which has a positive electric charge.Outside the nucleus are electrons, which have a negative charge.Asteroids that pass close to the Earth are called near-earth objects.Asteroids and comets are objects that orbit our Sun but are smaller than planets.The layer of gases just above Earth’s surface is our atmosphere.The atmosphere is made up of gases such as oxygen and nitrogen.Without an atmosphere, there would be no life on Earth.1.If the collide with Earth they could cause an extinction event.2.A force can increase or decrease the speed of an object, and it can change the direction of motion.3.What keeps the Earth in orbit around the sun?4.It moves in an orbit around the Sun because of the gravitational force between them.