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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
Hydrogen is located in the first row of group 1. It is separated by a slight space because it is unique in its properties as it can behave like a nonmetal despite being in group 1, which typically contains metals.
What are the main groups in the modern periodic table of elements?
Groups
- Group 1 is the Alkali Metals
- Group 2 is the Alkaline Earth Metals
- Groups 3 through 12 are the Transition Metals (includes the Lanthanide [elements 58-71] and Actinide Series [elements 90-103])
- Group 13 is the Boron Group
- Group 14 is the Carbon Group
- Group 15 is the Nitrogen Group
- Group 16 is the Oxygen Group
- Group 17 is the Halogens
- Group 18 is the Noble Gases
Why does size of an atom decrease across the period?
as you go from left to right across the periodic table, you are adding one more proton every time hence increasing the nuclear charge of the atom. An increased nuclear charge means the nucleus attracts the electrons more to it hence the size of the atom decreases as it "tightens". hence the atomic radius decreases every time.
What is the abbreviation for helium on the periodic table?
The abbreviation for helium on the periodic table is He.
How were the symbols of the elements devised?
I am presuming that by 'periodic elements' you are meaning modern elements, as opposed to Aristotle's fire, earth, air, and water, and aether.
There was no periodic law until 1869, so no element becomes 'periodic' until after that date -- hardly 'ancient'.
The seven metals known to the ancients were associated with the known heavenly bodies, and therefore inherited their astrological symbols
Moon silver
Saturn lead
Jupiter tin
Venus copper
Mercury mercury
Mars iron
Sun gold
The two non-metallic elements known to the ancients were sulfur and carbon. Sulfur has several different alchemical symbols associated with it, but the simplest and most plausibly ancient is an equilateral triangle on its flat base with a + sign hanging from the centre of the base. About carbon I have no idea.
How many valence electrons consult of the periodic table chorine?
Chlorine (Cl) has 7 valence electrons, as it is in Group 17 or 7A of the periodic table. This means it has 7 electrons in its outermost energy level.
Elements with atomic numbers greater than 92 are referred to as transmutation elements because they are typically created artificially through nuclear reactions involving the bombardment of lighter elements with high-energy particles. This process involves changing one element into another through nuclear transmutation. Some of these transuranium elements are not found in nature and can only be produced in nuclear reactors or particle accelerators.
Can mean a building floor or a table?
A floor typically refers to the level of a building, while a table is a piece of furniture with a flat top supported by legs. Both can be used for various functions such as dining, working, or displaying items.
What indicator would you use to determine the strength of a base?
At equivalence the only species present will be NaCl(aq) & H2O(l)
The solution of a salt of a strong acid and a strong base will have a pH=7
NaCl(aq) will have a pH=7
A suitable indicator would be bromothymol blue (pH range 6.2 - 7.6) or phenol red (pH range 6.8 - 8.4)
Strong Acid - Weak Base titrationHCl(aq) + NH3(aq) -----> NH4Cl(aq)NH4Cl is the salt of a strong acid & a weak base, so a solution of NH4Cl will have a pH < 7 (NH4+ is a weak acid)
A suitable indicator would be methyl orange (pH range 3.1 - 4.4) or methyl red (pH range 4.4 - 6.0)
Weak Acid - Strong Base titrationCH3COOH(aq) + NaOH(aq) -----> CH3COONa(aq) + H2O(l)CH3COONa is the salt of a weak acid & a strong base, so a solution of CH3COONa will have a pH > 7 (CH3COO- is a weak base)
A suitable indicator would be phenolphthalein (pH range 8.3 - 10.0) or thymol blue (pH 8.0 - 9.6)
Why is the magnesium the most reactive metal among silver copper lead zinc and iron?
Magnesium is the most reactive metal among silver, copper, lead, zinc, and iron because it has a high tendency to lose electrons, making it readily form compounds with other elements. Its outer electron configuration makes it easier for magnesium to react with other substances compared to the other listed metals.
Are there more elements or non-elements?
There are more non-elements than elements. Non-elements refer to everything that is not classified as an element, such as compounds, mixtures, and substances that do not fit the definition of an element.
What is the valency of the last element in the 3rd group of modern periodic table?
The last element in the 3rd group of the modern periodic table is gallium, with the symbol Ga. Gallium has a valency of +3, meaning it tends to lose three electrons to achieve a stable electron configuration.
Did mendeleev's original table could accommodate elements that did not even exist?
Yes, Mendeleev's original periodic table had gaps to accommodate elements that were yet to be discovered. He even successfully predicted the properties of some of these missing elements based on his table's structure.
What is a semi metal other than silicon?
Apart from Silicon, the following elements are considered as semi-metal(metalloids) :-
- Boron
- Germanium
- Arsenic
- Antimony
- Tellurium
- Polonium
However, not all sources consider Polonium to be metalloid whereas some allotropes of elements like phosphorous, selenium etc. also show metalloidic behavior.
What product is created from combining barium chloride and sodium sulfate?
Potassium and nitrate don't react, stay unchanged as hydrated ions in solution, called spectator ions.
Only sulfate and barium ions react by precipitating to solid.
(SO42-)aq + (Ba2+)aq --> (BaSO4)s
:)
What is the most dense element from the periodic table?
Osmium is the densest of the elements. The most dense pure metal is osmium, Os, with a density of 22.61 g/cm3 (that's about twice the density of lead).
Other very dense metals are:
iridium, Ir, 22.56 g/cm3
platinum, Pt, 21.4 g/cm3
rhenium, Re, 21.0 g/cm3
neptunium, Np, 20.4 g/cm3
plutonium, Pu, 19.8 g/cm3
gold, Au, 19.3 g/cm3
tungsten, W, 19.3 g/cm3
mercury, Hg, 13.53 g/cm3
Lead, Pb, which is usually considered pretty dense, is only 11.4 g/cm3! In case this isn't enough, lead will float on liquid mercury, which has a density of 13.5 g/cm3.
Which element has a larger radius nickel or platinum?
Platinum; it has two more electron shells than nickel.
What is the same group of periodic table as magnesium?
Magnesium belongs to group 2 (alkaline earth metals) in the periodic table. Elements in the same group as magnesium include beryllium, calcium, strontium, barium, and radium. They all share similar chemical properties due to having the same number of electrons in their outermost shell.
What is the number one metal on the periodic table?
The number one element on the periodic table is hydrogen. It is not a metal, but the lightest and most abundant element in the universe.
How is oxygen processed for us?
Oxygen is inhaled through the respiratory system, where it enters the lungs and diffuses into the bloodstream. It is then transported by red blood cells to various tissues and organs in the body for cellular respiration. During cellular respiration, oxygen is used by cells to produce energy in the form of adenosine triphosphate (ATP) through the process of oxidation.
Which list of molecules is arranged in order of increasing size?
- Oxygen, nitrogen, chlorine, bromine
- Water, ammonia, methane, hydrogen sulfide
- Carbon monoxide, carbon dioxide, methane, ethylene
The correct answer is option 2: Water (H2O) < ammonia (NH3) < methane (CH4) < hydrogen sulfide (H2S).
What are the characteristics of calcium's family?
The element calcium (Ca) is found in Group 2 of the peroidic table, and that makes it an alkaline earth metal. It is fairly reactive, and is not found free in nature. In compounds, it forms the +2 ion as it readily loans out its two valence electrons.
Calcium is a silver metal, but if exposed to air, it will rapidly corrode at it reacts with nitrogen and oxygen. In doing so, it will form a nitride and oxide coating. This metal is extremely common in nature (though in its ionic form in compounds), and it is an essential element for life. Aside from its reactivity as cited, it will burn brightly, though it is difficult to set ablaze. In burning, it will display a bright brick-red flame and cannot be extinguished with water.
Difference between internal combustion engines and external combustion engines?
Internal combustion engines burn fuel inside the engine to generate power, while external combustion engines burn fuel outside the engine and use the resulting heat to create power, such as in steam engines. Internal combustion engines are more common in vehicles due to their compact size and efficiency, while external combustion engines are used in specific applications like power plants and some marine propulsion systems.
