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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
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?
1) elements are composed of atoms 2) atoms of same elements = 3) atoms of different elements not = 4) atoms fomr compounds in definite ratios H2O
Which two of the three statements that make up Dalton's atomic theory are no longer regarded as true?
All the atoms in elements are not a like.
What are three things that the periodic table can tell me?
the properties, the atomic number, and atomic mass
What elements on the periodic table are usually identified with three things?
Symbol, atomic number, and atomic weight.
What chemical element has atomic number 35?
There is no such element. Atomic numbers represent how many protons are in the nucleus of an atom. Lithium's atomic number is three; it has three protons. An atom with 35.543 protons can't exist because there can't be a fraction of a proton - how can you have 35 and .543 protons? I think perhaps you confused atomic number with atomic mass. Chlorine's atomic mass is 35.543 grams.
What are the three main points to John Daltons atomic theory?
1) elements are composed of atoms 2) atoms of same elements = 3) atoms of different elements not = 4) atoms fomr compounds in definite ratios H2O
Name three observations made by Herry Hess to support his theory?
he was born in Arizona
Which two of the three statements that make up Dalton's atomic theory are no longer regarded as true?
All the atoms in elements are not a like.
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
