0
Periodic Table
The Periodic Table is a tabular arrangement of the elements in increasing order oftheir atomic numbers, so that elements with similar properties are in the same column. There are 18 columns, called groups, and seven rows, which are called periods, in the modern periodic table. Questions about the Periodic Table: its history and creation, trends, groups/families, and periods are asked in our Periodic Table category.
11,356 Questions
What is one way all symbols for elements are the same?
It is not possible because we need a differentiation between elements, including different chemical symbols.
What are some uses of phosphorus pentabromide?
Phosphorus pentabromide is commonly used as a reagent in organic synthesis to convert alcohols to alkyl bromides. It is also used in the synthesis of pharmaceuticals and agrochemicals. Additionally, it is utilized as a brominating agent in some chemical reactions.
Nonreactive gases are gases that do not easily undergo chemical reactions with other substances. Examples include noble gases like helium, neon, and argon, as well as diatomic molecules like nitrogen and oxygen in their elemental forms. These gases are often used in inert environments or as protective atmospheres in various industrial processes.
What block of elements do the halogens belong to?
The halogens belong to Group 17 of the periodic table, also known as the halogen group. This group includes elements such as fluorine, chlorine, bromine, iodine, and astatine. They are highly reactive nonmetals that readily form compounds with other elements.
Which element is a monatomic gas with two positive charges?
Helium is a monatomic gas with two protons, giving it a two positive charges.
Yes, aluminum is a metal. It is a lightweight and versatile element commonly used in various industries such as aerospace, transportation, and construction due to its high strength-to-weight ratio and corrosion resistance.
What is the balanced chemical formula of iron II sulfate plus sodium hydroxide?
The balanced chemical formula for the reaction between iron(II) sulfate and sodium hydroxide is: FeSO4 + 2NaOH -> Fe(OH)2 + Na2SO4.
In order to delete a record in a table you must first?
Identify the record you want to delete based on a specific criteria, such as an ID or value. Then, write a SQL DELETE statement with a condition that matches the record you want to delete. Finally, execute the SQL statement to remove the record from the table.
Can hydrogen can be place in group 7?
No, hydrogen does not belong to group 7 of the periodic table. It is placed in group 1 since it has 1 electron in its outer shell.
What name is given to each horizontal row?
Each row on the periodic table is called a period, while each column is called a group.
The valency of sulfite (-SO3) is 2-, meaning it has a charge of -2. This is because sulfur typically has a valency of 6 due to its position in the periodic table, and in sulfite it forms three single bonds with oxygen atoms and has one extra electron, giving it a total charge of -2.
How do you find the concentration of 3.50g of potassium chromate in 100 ml water?
K2CrO4
Molarity (concentration) = moles of solute/Liters of solution (100 ml = 0.100 Liters )
Find moles K2CrO4 first.
3.50 grams = (1 mole K2CrO4/194.2 grams)
= 0.01802 moles K2CrO4
----------------------------------------------next
Molarity = 0.01802 moles K2CrO4/0.100 Liters
= 0.180 M K2CrO4
-------------------------
BaF2 would be the best conductor in the pure liquid or molten state due to its ionic nature and ability to dissociate into ions. Other compounds listed are covalent in nature and do not dissociate into ions easily in the liquid or molten state, resulting in poor conductivity.
Why do the elements in the group 1 and 2 react with group 17?
Elements in group 1 have 1 electron in their outer shell. Group 7 electrons have 7 electrons in their outer shell. This means that the group 1 element needs to give its electron to the group 7 element so that they both have full outer shells, making them stable. By a school boy in yr. 10
Are reduction reactions and displacements the same thing?
Reduction reactions involve the gain of electrons by a molecule or atom. Displacement reactions involve the exchange of ions between two compounds. While reduction reactions can be involved in displacement reactions, they are not the same thing.
How many atoms are in 5 moles of lithium?
1 mole of lithium has 6.023 x 1023 atoms.
So 5 moles will have 30.115 x 1023 atoms
Did the periodic table come before the atomic model?
The periodic table came after the atomic model. The modern periodic table was developed based on the atomic structure proposed by scientists such as John Dalton, J.J. Thomson, Ernest Rutherford, and Niels Bohr. Mendeleev's periodic table was published in 1869, while the atomic model continued to evolve throughout the late 19th and early 20th centuries.
What element has 125 atomic number?
The element with atomic number 125 is unknown, as it has not been discovered or named yet. Elements beyond uranium (atomic number 92) are typically synthesized in laboratories and have very short half-lives.
What is the radioactive isotope in the periodic table?
A normal periodic table does not list isotopes, but elements, almost all of which occur in more than one isotope, and there is probably at least one radioactive isotope for every element. Instead of the periodic table, a table of nuclides is needed to answer this question.
Fluorine has the smallest atomic radius, while Francium has the largest atomic radius.
What instrument lead to the discovery of the neutron?
The invention of the cloud chamber by physicist Ernest Rutherford in 1911 led to the discovery of the neutron by James Chadwick in 1932. The cloud chamber allowed researchers to observe the tracks of subatomic particles, which helped Chadwick identify the previously unknown neutron.
Yes, but they lose the 'identity' of the element when they are divided.
Atoms were once thought to be indivisible units of an element - the smallest thing that retained the characteristics of an element. The word comes from the Greek for indivisible/uncuttable ~ a+ temnein.
It is now known that atoms contain protons, neutrons and electrons and that even these are composed of smaller particles called quarks.
What is one part oxygen and two parts carbon?
The formula should be C2O, but there is no compound that way.
The other way around (one carbon and two oxygen) is known. It is carbon dioxide or CO2.
What is a large table that scientists use to find out information about metals and other elements?
The periodic table of elements
