1 – All living organisms are composed of cells. 2 – Animal cells are too small to be visible to the naked eyes. Some of these cells are so tiny that even 1 million of them together hardly cover a space as large as the pointed end of a pin. …
1 – The Periodic Table is a chart which arranges the elements in a useful and logical manner. 2 – Elements are listed in order of increasing atomic number , lined up so that elements which exhibit similar properties are arranged in the same row or column as each other. …
1 – Molecules and compounds are held together by forces called chemical bonds. 2 – There are two main types of bonds that hold most compounds together: covalent bonds and ionic bonds. 3 – Covalent Bonds – Covalent bonds share electrons between atoms. This happens when it works out for …
1 – The nucleus of an atom consists of protons and neutrons. 2 – The negatively-charged electrons are attracted to the positively-charged protons. 3 – The positively-charged protons repel each other and aren’t electrically attracted or repelled to the neutral neutrons , so you may wonder how the atomic nucleus …
1 – Everything around you is made up of molecules. This includes you! You are actually made up of trillions and trillions of different types of molecules. 2 – Molecule is a group of two or more atoms that stick together. 3 – Molecules are so small that nobody can …
1 – The atoms of an element can exist in different types. These are called isotopes. 2 – Isotopes are atoms that have the same number of protons and electrons , but a different number of neutrons. 3 – Changing the number of neutrons in an atom does not change …
1 – Each atom is made up of a nucleus and a number of electrons moving in orbital shells at great distances from the nucleus. 2 – Electrons are particles spinning and revolving around the nucleus of the atom similar to the earth rotating on its own axis as it …
1 – An atom is the smallest particle of an element still having the same chemical properties of the element. 2 – Atoms are the basic building blocks of matter that make up everyday objects. A desk , the air , even you are made up of atoms! 3 – …
1 – Oxygen is the most vital nutrient for the human body. You can survive several weeks without food , several days without water , but you cannot survive more than a few minutes without oxygen. 2 – It is a simple and indisputable fact – oxygen is necessary to …
1 – The noble gases are a group of elements in the periodic table. They are located to the far right of the periodic table and make up the eighteenth column. 2 – The elements that make up the family of noble gases include helium , neon , argon , …