This is the balance between the pull of protons on the valence electrons and repulsion forces from inner electrons. Transition metals have low shielding effect. Transition metals easily lose electrons or ionized easily.
Category Archives: Structure of an atom and the Periodic table
Ionization energy
Ionization energy is the minimum amount of energy needed to completely remove the valence electrons from the atom/ion and is directly related to the force of attraction on the electrons . The larger the nuclear charge and smaller radii of atom the larger the ionization energy (IE) . Ionization energy is also more for halfContinue reading “Ionization energy”
Ionization energy down the group.
Ionization energy is the minimum amount of energy required to completely remove electron (s) from a neutral atom in gaseous state . The ionization energy of the elements within a group generally decreases from top to bottom. This is due to electron shielding/screening. Screening is the ability of atoms inner electrons to shield it’s positivelyContinue reading “Ionization energy down the group.”
Atomic sizes across a period.
Atomic sizes ( in terms of radius) gradually decrease from Left to right across a period of elements. This is because within a period, all electron (s) are added to the same shell . However, at the same time the protons are being added to the nucleus making it more positively charged. The effect ofContinue reading “Atomic sizes across a period.”
Sodium is harder than potassium metal . Explain?
The smaller the atom in term of atomic radius,the higher the melting point of an element and hence the greater the metallic bond in the metals . Sodium has a smaller atomic radius ( atomic radius of the Alkali metals increases down the group) than potassium metal, therefore the orbital are nearer to the nucleusContinue reading “Sodium is harder than potassium metal . Explain?”
Why is an atom said to be electrically neutral?
In any given atom, the number of protons in the nucleus of an atom equals to the number of electrons in the energy level. The protons are positively charged while the electrons are negatively charged. For example, a sodium atom has 11p ,11e and 12n , the neutrons have no charge. The protons therefore hasContinue reading “Why is an atom said to be electrically neutral?”
Explain why hydrogen can be regarded as either a group i element or a group vii elements in the periodic table of the first 20 element ?
Explanation Hydrogen is the lightest element with 1 atomic mass unit , it is the first element in the first 20 elements in the periodic table, hydrogen exists in form of several isotopes . Hydrogen is found in combined form with other elements such as with oxygen to make up water and also in hydroxidesContinue reading “Explain why hydrogen can be regarded as either a group i element or a group vii elements in the periodic table of the first 20 element ?”
Isotopes
Isotopes are atoms of the same element, with the same atomic numbers but different mass numbers . Why do isotopes occur ? This is due to the difference in the number of neutrons in the nucleus of these atoms . Carbon has two isotopes, Carbon -12 and Carbon – 14 . Browse on
STRUCTURE OF AN ATOM AND THE PERIODIC TABLE . _Structure of an atom What is an atom ? An atom is the smallest particle of an element which can take part in a chemical reaction. – An atom has a diameter of 10–⁸ cm. ( 0.00000001) . – An atom is made up of three sub atomic particle; a) Protons b) Neutrons c) Electrons – The protons and neutrons are found inside the nucleus of an atom while electrons are found in the region around the nucleus ( in the shells or energy levels ) . – Protons are positively charged (+ve) while electrons are negatively charged (-ve) . The neutrons have no charge ( neutral particles ) . Why is an atom said to be electrically neutral ? In any given atom , the number of protons ( in the nucleus) equal to the number of electrons( in the shells ) p=e. Where p= protons e= electrons Why are protons and neutrons referred to as nucleons ? This is because both the protons and neutrons are found in the nucleus of an atom of an element.
✓ Lithium has three protons (3p) , three electrons (3e) and four neutrons (4n) and therefore it’s structure is ; Browse for more content
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