Explain why space junk is a hazard to an astronats or spacecraft

Space junk is travelling so fast that a collision with an astronaut or a spacecraft could be disastrous.

Explanation:

Space junk orbits the Earth at speeds of about 28 000 km/h.  

That's so fast that even an orbiting fleck of paint has enough kinetic energy to cause impact craters on the surface of a spacecraft. They are even more dangerous to an astronaut on a space walk.

Much of the space debris is larger and more dangerous than a fleck of paint.

One rough estimate of the amount of space debris is

      Size                Number of objects

< 1 cm                        200 000 000

1 cm to 10 cm                   700 000

> 10 cm                                 30 000

Satellites, etc.                       18 000

The chances of collision are small, but any collision can be disastrous.

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.