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Law of Conservation of Mass - No detectable gain or loss in mass occurs in chemical reactions. However, the state of a substance may change in a chemical reaction. For example, substances involving in a chemical reaction can change from solid states to gaseous states but the total mass will not change. Note that the energy released (exothermic) or adsorbed (endothermic) in a chemical reaction is a result of energy transfer between atoms and their environment.
Law of Definite Proportion - The elements in a given compound are always combined in the same proportion by mass. This law forms the basis for the definition of a chemical compound. For example, a water molecule (H2O) consists of two hydrogen atoms each of relative mass of 1 and one oxygen atom of relative mass of 16 (rounded to nearest integer number). By putting a sensible unit measurement this means that there are 2 g of hydrogen and 16 g of oxygen in a sample of 18 g of water. The ratio is 1 to 8. Thus, a sample of, say, 51.435 g of water always contain (51.435 x 1/9) 5.715 g of hydrogen and (51.435 x 8/9) 45.720 g of oxygen. The ratio, again, is 1 hydrogen to 8 oxygen. This rule applies for water found anywhere in the universe and the mass proportion is always the same for any given unit measurement (kilogram, pound etc.).
Law of Multiple Proportion - Whenever two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers. Take an example of two mineral samples iron pyrite (FeS2) and iron troilite (FeS). Both contain iron and sulfuratoms. However, for a given fixedamount of iron it requires exactly twice the mass of sulfur needed to make pyrite than that of troilite with the same amount of iron.
Wiki User
∙ 11y ago
- Law of conservation of mass: In a chemical reaction, matter is neither created nor destroyed.
- Law of definite proportions: A compound always contains the same elements in the same proportions by mass.
- Law of multiple proportions: When two elements form more than one compound, the ratios of the masses of the second element that combine with a fixed mass of the first element can be reduced to small whole numbers.
Wiki User
∙ 13y agoThere were actually four postulates:
1) All matter is made of atoms. Atoms are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangementof atoms.
Wiki User
∙ 12y agolaw of conservation of mass
law of definite proportion
law of multiple proportion
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What are the three main points to John Daltons atomic theory?
All matter is made up of tiny, indivisible particles called atoms. Atoms of the same element are identical in size, mass, and properties, while atoms of different elements differ in these aspects. Chemical reactions involve the rearrangement of atoms, but atoms are neither created nor destroyed in chemical reactions.
What elements on the periodic table are usually identified with three things?
Elements such as oxygen, silicon, and carbon are commonly associated with three things: atomic number, atomic mass, and chemical symbol. These properties help uniquely identify each element on the periodic table.
What are the main three parts of an electrons used in the current atomic theory that describe an electrons location?
The main three parts of an electron's location in the current atomic theory are energy level (or shell), sublevel (s, p, d, f), and orbital (specific region within a sublevel where an electron is most likely to be found). These components help to describe the position and energy of electrons within an atom.
Which two of the three statements that make up Dalton's atomic theory are no longer regarded as true?
The two statements that are no longer regarded as true in Dalton's atomic theory are: 1. Atoms are indivisible and indestructible (we now know that atoms can be divided into subatomic particles and can undergo nuclear reactions) and 2. All atoms of a given element are identical in mass and properties (we now know that isotopes exist, leading to variations in mass).
Use the Molecular orbital theory to describe covalent bonding?
In the molecular orbital theory, when two atoms come together to form a covalent bond, their atomic orbitals overlap to create molecular orbitals. If the atomic orbitals overlap in phase (constructive interference), a bonding molecular orbital is formed, which is lower in energy than the original atomic orbitals. If the atomic orbitals overlap out of phase (deconstructive interference), an antibonding molecular orbital is formed, which is higher in energy than the original atomic orbitals. The overall stability of the molecule is determined by the balance between bonding and antibonding orbitals.
Name three observations made by Herry Hess to support his theory?
he was born in Arizona
Analyze the three parts of the cell theory and describe two observations of early scientist that support it?
They have money
Which two of the three statements that make up Dalton's atomic theory are no longer regarded as true as stated by Dalton's?
All the atoms in elements are not a like
What is the three theory?
the three date theory is a theory that after 3 dates the girl will put out.
What is the three date theory?
the three date theory is a theory that after 3 dates the girl will put out.
What three types of evidence provided support of the theory of sea-floor spreading?
three are : eruptions of molten material magnetic stripes in the rock of the ocean floor and the ages of the rocks themselves :)
What three types of evidence provided support of the theory of sea floor spreading?
three are : eruptions of molten material magnetic stripes in the rock of the ocean floor and the ages of the rocks themselves :)
What are three forms of evedence used to support th big bang theory?
Three important pieces of evidence are:* The redshift of distant galaxies. This means that galaxies are moving away from us. * The percentages of elements and isotopes. This closely matches predictions from theory. * The cosmic background radiation. This, too, closely matches predictions from theory.
What are three concepts of sociocultural theory?
what three concepts are fundamental to vygotsky's sociocultural theory.
What are three types of evidence provided support for theory of sea?
eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves
Which theory is a reworking of Maslow's need hierarchy and is better supported by additional research than is Maslow's theory?
Self-determination theory is a reworking of Maslow's need hierarchy theory and has gained stronger empirical support. It emphasizes three basic psychological needs: autonomy, competence, and relatedness, which are essential for intrinsic motivation and well-being.
What are the three natural phenomena that support the kinetic?
The three natural phenomena that support the kinetic molecular theory are diffusion (movement of particles from high concentration to low concentration), Brownian motion (random motion of particles in a fluid medium), and pressure (resulting from particles colliding with the walls of their container).
