Many human activities result in carbon dioxide emissions. Our carbon footprint is a measure of how much carbon dioxide we each cause to be produced.
(a) Why should we be concerned about our carbon footprint?
(b) Most power stations in the UK burn coal.
Coal was formed from tree-like plants over millions of years.
Suggest why burning wood instead of coal would help to reduce our carbon footprint.

: the average human-driven CO2 emissions per year climbed 1.4%

every household makes about 7 tons worth of Co2

A C02 footprints are produced at such high rates and hurts plants and the environment

B coal is a very inexpensive and efficient way to generate electricity. Since its a large quantity of them which still produces alot co2  unlike wood, burning wood doesn't  produce as much but it's much harder to ignite and get to last because it takes coal almost 100 degrees and wood takes about 700 degrees

d.) circle motion requires a force to give it a centripetal acceleration.

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.