asteroid hitting earth

What would happen to humans if an asteroid 1,000 meters in diameter and weighing 100,000 tons collided with Earth?
An asteroid with a diameter of 1,000 meters and weighing 100,000 tons colliding with Earth will lead to catastrophic consequences on a global scale.
The Earth was heavily contaminated with mercury before the collision with the Chicxulub meteorite
A new study has just published that before Chicxulub asteroid hit the Earth 66 million years ago, dinosaurs and other living creatures were faced with toxic levels of mercury.