What elements do volcanic rocks have?
1 As you walk around, you will notice volcanic rocks and mountains on the island that are made up of mixtures of oxygen and silicon with magnesium, aluminum, potassium, iron, and small amounts of other elements.
Which of the following elements do living things have?
The four elements common to all living organisms are oxygen (O), carbon (C), hydrogen (H), and nitrogen (N).
Is it true that a few elements combine to make many compounds?
The same thing is true of matter in general. By combining just a few different elements, you can form many different chemical compounds.
What is two or more elements combined?
When two or more elements combine to form a new substance, it is called a compound. There are many different types of compounds, because atoms of elements combine in many different ways to form different compounds.
What is it called when two chemicals are combined?
A combination reaction (also known as a synthesis reaction) is a reaction where two or more elements or compounds (reactants) combine to form a single compound (product).
What is it called when two or more atoms are chemically combined?
A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together.
When two atoms are combined they are called?
A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different elements, we call that a compound.
How do you combine atoms chemically?
Most interactions among atoms take place in the outermost shell of each atom. The number of each electron in this shell determines how an atom combines with other atoms to form compounds. When atoms combine they gain, lose or share electrons in such a way that the outer shells become chemically complete.
How do you know if an atom is stable?
An atom is stable if the forces among the particles that makeup the nucleus are balanced. An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom’s nucleus may result from an excess of either neutrons or protons.
How do you know if an element is chemically stable?
– An atom is chemically stable if its outer energy level (valence level) is completely filled with electrons. (8 electrons) – Energy levels are filled by elements gaining, losing, or sharing electrons.
What atoms are chemically stable?
Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons. Sodium atoms have 11 electrons. Two of these are in the lowest energy level, eight are in the second energy level and then one electron is in the third energy level.
Which is more stable atom or ion?
While atoms are stable by default whereas ions become stable by loss or gain of electrons. Ions are more stable because their valence shell is fulfilled and therefore no sharing or bonding of electrons take place. While atoms do not have fulfilled valance shell and so, Ions are considered more stable.
What is the strongest chemical bond?
Answer: Covalent bond is the strongest bond.
Why do atoms want 8 electrons?
Atoms need 8 electrons in their outermost shell for elements due to the Bohr-Bury rules one of which states that the outermost shell of an atom cannot contain more than 8 electrons in their outermost shell and also that an atom to gain stability needs at least 8 electrons in their outermost shell.
What is the 2-8-8 rule in chemistry?
There is a 2-8-8 rule for these elements. The first shell is filled with 2 electrons, the second is filled with 8 electrons, and the third is filled with 8. You can see that sodium (Na) and magnesium (Mg) have a couple of extra electrons. They, like all atoms, want to be happy.
Do atoms always want 8 electrons?
Lewis formulated the “octet rule” in his cubical atom theory. Atoms will react to get in the most stable state possible. A complete octet is very stable because all orbitals will be full. Thus, an atom continues to form bonds until an octet of electrons is made.
Why are there only 8 electrons in the outer shell?
This is due to the quantum nature of the atoms, where electrons are arranged into shells: there are 2 electrons in the first called the K shell, 8 in the second (L-shell), 18 in the third (M shell). …
What is octet rule Class 9?
The octet rule dictates that atoms are most stable when their valence shells are filled with eight electrons. The octet rule is only applicable to the main group elements. The molecules of the halogens, oxygen, nitrogen, and carbon are known to obey the octet rule.
Why can an atom have no more than eight valence electrons?
octet rule: Atoms lose, gain, or share electrons in order to have a full valence shell of eight electrons. Hydrogen is an exception because it can hold a maximum of two electrons in its valence level.
Can an atom have more than 8 valence electrons?
Unlike atoms from periods one and two that only have the s and p orbitals (total of 8 valence electrons), atoms like phosphorus, sulfur, and chlorine can have more than 8 electrons because they are not restricted to the s and p orbitals and have a d orbital for additional electrons needed for bonding.
What does it mean if an element has 8 valence electrons?
Atoms of group 18 elements have eight valence electrons (or two in the case of helium). These elements already have a full outer energy level, so they are very stable. As a result, they rarely if ever react with other elements. Therefore, it is very reactive and gives up electrons in chemical reactions.