Atomic number

Atomic number, is a correct answer. Atomic number is the total number of proton of the element. (Gilbert, 2012) It is always used to differentiate the elements since every element have their unique atomic number. The differences of atomic number enabled elements to react with other substances differently. For example, Neon which have atomic number of 8, acts like an inert gas. Meanwhile group 1 element Sodium which have atomic number of 11, reacts vigorously with water. Such characteristic have

As you move from the left of a period to the right of a period, the atomic radius of an atom decreases. This is because as you move to the right of a period on the periodic table, the atomic number increases, and because the atomic number determines the number of protons, the number of protons in the nucleus also increases. This means that the nucleus will continue to become more positive as the atomic number increases. The electrostatic force of attraction states that oppositely charged particles

based on their atomic number. Atomic number, or the number of protons in the nucleus, is what distinguishes each element on the chart. In the original design of the periodic table, elements were organized based on their atomic mass, however it was later discovered that placing the elements based on atomic number made more sense, as it created a pattern and allowed it to be known what elements are yet to be discovered. Generally, however, the atomic mass increases with the atomic number. Hydrogen is

3. Samples of natural selenium contain six stable isotopes. these isotopes have the same number of proton & electrons in each atom they differ in the number of neutrons in each atom, the atomic mass, & their nuclear stability Electron configuration 1S2, 2S2, 2P6, 3s2, 3p6, 4s2, 3d10, 4p4 Indicate the number of unpaired electrons in the ground-state atom it has 2 unpaired electrons in the 4P orbital. in a chemical reaction it is likely to take 2 electrons & become Se-2 or likely to do 2 covalent

Periodic Table The periodic table is arranged in different ways. The periodic table organizes the elements in horizontal rows, or periods, by order of increasing the atomic number, which equals the number of protons in the atomic nucleus of each element. Elements are arranged in the periodic table in order of its increasing atomic number. The table allows chemists to make accurate predictions of physical and chemical properties from any element. On the periodic table it features: groups- vertical columns

development of atomic theory, and made science changing discoveries that are still today quite impressive, even in comparison to modern day scientists. There are countless scientists involved in the evolution of atomic theory, but less than 50 have majorly impacted the way we view atomic theory today. Discovery and experimentation on the atom first began in the Greek Era with scientists as old as Democritus and Aristotle. Democritus was believed to be the first person to touch on the atomic theory. He

has atomic number 15 and it is found in the periodic table with P. Phosphorus exists in several forms like: white phosphorus, red phosphorus, violet phosphorus and as a black phosphorus. These types of phosphorus have different properties and are called allotropes. It has a high reactivity and it is never found as a free element on earth. The phosphorus can show the phenomenon of luminescence. Phosphorus is discovered by Henning Brand. He isolated phosphor form the urine. Phosphorus atomic weight

different. Krypton’s atomic number is 36. Its atomic mass is 83.798 units. The number of protons in an element, which is also the atomic number, is 36. It also

Chemistry Mid-term Exam Version 2/23/15 Name: Leila Marshall Student number: JM1512137 Directions: It is important that you provide answers in your own words. Please focus only on information from the text/eBook to create your own solutions. Please do not use direct information from an outside source (especially copying and pasting from an “answer” website). Use of direct information from an outside source is against school

carbon and silicon and form their corresponding compounds. Lanthanide Contraction Back to Top The atomic size or ionic radii of tri positive lanthanide ions show a steady and gradual decrease with the increase in atomic number from La to Lu. Although they show some irregularities but ionic radii decrease steadily from La to Lu. This gradual decreasing in the size with increasing atomic number is called lanthanide contraction. Cause of lanthanide contraction The major cause for lanthanide contraction