At the center of every atom lies a small, dense "nucleus" that is positively charged.
Atom is the smallest unit of matter. It is made up of electrons, protons and neutrons. Electrons are negatively charged particles that are found scattered in different energy levels outside the nucleus. Protons are positively charged particles present inside the nucleus. Neutrons do not carry charge and found inside the nucleus. Thus, protons and neutrons make up the nucleus of an atom. Since, protons are positively charged and neutrons are uncharged particles, the charge of nucleus becomes positive.
A) Selenium - is apart of Sulfur family
If the core were to cool completely, the planet would grow cold and dead. It also would get a little dark: Power utilities pull radiant heat from Earth's crust and use it to heat water, the steam from which powers turbines to create electricity.Cooling also could cost us the magnetic shield around the planet created by heat from the core. This shield protects Earth from cosmic radiation. The shield is created by a convection process caused by constantly moving iron. Like the planet itself, Earth's core is constantly spinning. Some scientists think it's moving even faster than the rest of the planet. The friction converts kinetic energy into electrical and magnetic energy that forms the field, which deflects harmful, charged particles emanating from the sun toward the north and south poles. Your welcome :)
The mass sample of nicotine combusted = 2.625 mg (given)
Mass of
produced = 7.1210 mg (given)
Mass of
produced = 2.042 mg (given)
Molar mass of
= 44 g/mol
Molar mass of
= 18 g/mol
Percentage of Carbon =
%
Percentage of hydrogen =
%
Now, for percentage of nitrogen =
%
Calculating the moles of each element:

- For


- For


- For


Dividing with the smallest mole value to calculate the molar ratio of each element:



Hence, the empirical formula for nicotine is
.