Also in which group can we find the other metals.and how many noble gases do we have? what make the noble gases stable.
135871
Alkaline earths are in the second column on the periodic table (Be, Mg, Ca, etc.)  They have two electrons in their outer (valence) shell, which they readily give away to form ions with a 2+ charge.  They are not as reactive as the alkali metals (in column 1), but are more reactive than most other elements.  (Reactive refers to how readily they will form compounds with other elements.)\n\nThe noble gases are He, Ne, Ar, Kr, Xe, and Rn.  They are stable because they have full valence shells.  For example, He has 2 electrons, so the first shell is filled, as it can only hold 2. He has 10 electrons, so with 2 in the first shell and 8 in the second, the valence shell is again full, since the second shell can hold up to 8 electrons.  And so on.  The third shell can also hold 8, so Argon's 18 electrons fill its three shells completely.  The fourth shell can hold up to 18 electrons, which is why Krypton has a full four shells with 36 electrons (2+8+8+18).
62213
helium neon argon krypton xenon radon\nyou probably do not need to know ununoctium because it was just discovered, is radioactive, and radioactively decays in a few seconds.
187221
Noble gasses for the RR and utilities.
396718
Re:  For Helium, the "2" is called the atomic number and it means that Helium has 2, protons, 2 nuetrons and 2 electrons.\n\nFor Lawrencium (Lr) it should show 103 as its atomic number.  That means that Lr has 103 protons, 103 neutrons and 103 electrons.  \n\nThe 2, 8, 18, 32, 32, 8, 3 numbers are showing electrons per shell (different subject) but you'll see that if you added all the numbers 2+ 8+ 18+ 32+ 32+ 8+ 3 = 103.  103 is the total number of electrons Lr has.   \n\n____________________________________________\n\n\n\n\nFor a Normal Neutral Atom, the number of protons (p+), neutrons (n) and electrons (e-) are all the same. \n\nJust look up the atomic number from the periodic table to determine them.\n\nFor example:\n\nC: 6p, 6n, and 6e-.\nN: 7p, 7n, and 7e-.\nK: 19p, 19n, and 19e-.\n\nNow, Determine the number of p, n, and e- for Ca.\n\n\n\n\n\n\nIf you guessed, 20p, 20n, and 20e-, you are Correct!\n\n\nNote that, if you add the number of the atom's p and n you will get the Mass number (Z). \n\nThe periodic table shows Z of calcium as 40.078 because 20p + 20n = 40 (amu) \n\nAnother Example: Oxygen, having atomic number of 8, will have:\n8p, 8n, and 8e-. This means that Oxygen will have the mass number of 16 because; p + n = Mass number (Z).\n\n______________________________...\n\nFor Isotopes:\nIsotopes are atoms that have same number of protons but different number of neutrons.\n\nYou've already seen that normal Carbon has: 6p, 6n, and 6e-.\n\nThis normal carbon is called "Carbon-12". The "12" denotes its Mass number (Z). Which is p + n.\n\nThere are isotopes of Carbons and one of them are Carbon-13. Since you already know that Carbon must have 6p, Carbon-13 has 7n. 13 - 6 = 7. The number of the electrons are still the same as number of proton. \n\nIn another words, simply subtract the number of protons from mass number to determine the number of neutrons.\n\nNow, determine the number of p, n and e- of Fluorine-19:\n\n\n\n\n\nIf you guessed 9p, 10n, and 9e-, you are Correct!\n\n______________________________...\n\nFinally, there are ions. Ions means that an atom has either gained or lost electrons. Keep in mind that eletrons are NEGATIVE in nature (e-) and when an atom Gains e-, it becomes More negative.\n\nFor example: Fluoride ion, F- means that it has GAINED one electron compared to its neutral F state. Therefore;\n\nF has 9p, 9n, and 9e-, But F- has 9p, 9n, and TEN e-.\n\nO has 8p, 8n, and 8e-, But O2- has 8p, 8n and TEN e-, because O2- means that it has Gained 2 more electrons than its normal O state. \n\nNow, determine the p, n and e- for P3-.\n\n\n\n\n\nIf you guessed 15p, 15n, and 18e- you are Correct!\n\nFor atoms that have positive charges (cation), remember that they LOSE e- to become positive. So, Li+ has 3p, 3n and 2e-. \n______________________________...\n\nKeep in mind that you need to know how to combine all three of the ideas mentioned above. For example, you may be requested to determine the p, n and e- of Magnesium-25 ion. \nYou need to know that since Magnesium is in Group IIA, it will turn into 2+ ion. Therefore Magnesium-25 ion will have 12p, 13n, and 10e-. \n\nI hope this answers your question. Good luck!
482039
Noble gases are also called inert gases because they do not react chemically.  There the one in the last column of the table.  Their last electron layer is full (all 8 electrons --2 for helium-- are there) and that's why they don't (usually) form bonds.
146056
Yes, you can add Rhodium, Irridium and Palladium among others.\n\nBasically it's those elements that have the outer electron d-shell filled completely. They therefore interact weakly with other elements.
274018
Guess a group 3 metal such as boron or Aluminium
521772
Well the reason it is so hard to obtain those pure elements is basically stability. Every atom ,but the Noble gases, wants an octet, 8, valence electrons. So these atoms bond with other atoms of other elements, rendering them as impure, to have that octet. \n\nI.E:They as in Zirconium and Hafium would rather be bonded together than pure. Though there are ways to pull the bonds apart.\nFor example is the separation of hydrogen and Oxygen when a current is pased through H2O, water.
323847
First of all: God doesn't exist so that explanation is out.\n\nHydrogen was not the only element that existed right after the big bang.  The universe was 75% Hydrogen and 25% Helium with trace amounts of what astrophysicists call 'metals' (which in astrophysics means anything other than Hydrogen or Helium and so rather confusingly includes such things as Oxygen and Nitrogen).\n\nThe rest were created by nuclear fusion reactions inside stars until Iron because a net energy gain is possible when fusing anything lighter than Iron.  Those heavier than Iron were created in supernova when the energy of the Iron core of a really massive star collasping into a Neutron Star allowed for Iron to be fused and some of the heavier stuff (includings things even heavier than Uranium) were expelled and ended up becoming part of our planet.\n\nThat is why there are 90 naturally occuring elements on Earth (not 92, there are two elements lighter than Uranium which don't occur naturally on Earth).
253609
Hmm, kinda hard to help you here, since we can't see all your options for the first two.  The ellipses (. . .) indicate that you have more in your message than is being displayed.  Perhaps if you retyped them, it would be easier for us to help.\n\nHere's what I *can* help with:\n\nHalogens:Reactive as Noble Gas:STABLE\n(the halogens are very reactive gases, while the noble gases are extremely stable, almost to the point of being inert)\n\nOxygen:molecule as chloride:ION\nOxygen gas is a molecule, while chloride is the ionic form of chlorine\n\nRatio:subscript as oxidation number:CHARGE\nthe ratio of components in a mixture is denoted by the subscripts, as the oxidation number of an atom is denoted by its ionic charge
488160
1. Not sure\n2. Electrons in their outer shell\n3. Shells of electrons?\n4. Metalloids
443325
The correct answer is 3 Nitrogen \n\n7 electrons as follows 1s2 2s2  2p3  . The sublevel 2p3 can theoretically contain  6 electrons and has only 3\n\n\nHelium and neon are noble gases. All the sublevels are filled\n\nBeryllium  has  4 electrons and  2 on shell K 2 and 2 on sublevel 2s complete
579324
Because even though it is a radioactive element it's half-life will be over 1/2 million years making it a stable element.  It has what is termed in physics as an 'island of stability' which describes the possibility of elements which have stable 'magic numbers' of protons and neutrons.
51253
Hydrogen is not in a group with other families. It actually is in group 1 of the periodic table. It is a diatomic atom when it combines with other elements.
366870
1 Aluminum (III) Oxide\n\n2 Iron (II) Sulfide\n\n3 Silver (I) Nitrate\n\n4 Tin (IV) Nitrate\n\n5 Carbon Monoxide\n\n6 Magnesium Sulfide\n\n7 Lead (II) Oxide\n\n9(8?) Sulfur Hexafluoride\n\n10 Mercury (I) Chloride
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Just in general\n\nAlkali Earth Metals- Pretty reactive they are found in many compounds\n\nBoron group- Low reactivity\n\nCarbon group- More reactive then boron group but still pretty low\n\nNitrogen group- More reactive then Carbon group\n\nOxygen group- Very reactive oxygen has an unually high affinty for electrons relative to where it is on the periodic table\n\nHalogen group- Even more reactive than oxygen th&#92;ey have very hi\naffinity for electrons\n\nNoble gases- Basically inert, they have a full outer orbital of electrons and will only react in rare cases such as with flourine
423632
Nitrogen might be what you are looking for as it is a gas and is next to Oxygen in the periodic table so it has similar mass.\n\nBut as the person above has said, some kind of gaseous sulfur would have the closest properties to oxygen.