Achild sits on a partially filled balloon and decreases the volume by half. what happens to the pressure inside of the balloon?

The pressure inside of the balloon increases by half

Explanation:

We can think of the balloon as a container of air ,which is a gas with a determinate volume and pressure.

According to Boyle's law the volume of a gas is inversely proportional to its pressure.

For example, if a balloon volume is 3 liters  and the pressure inside the balloon 20 pascal and a man inflates the balloon up to 6 liters the pressure inside the balloon now is 10 pascal.

When a tank with 40 liters of nitrogen and 100 pascal of inner pressure is  compressed to 200 pascal of pressure, the volume goes down to 20 liters

So  when the volume increases the pressure decreases and vice versa

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.