Answer:
A) All the elements are composed of atoms.
d) Atoms cannot be created or destroyed in any chemical changes.
c) An atom of one element cannot be changed into an atom of a different element.
Explanation:
The main postulates of Dalton atomic theory was:
1) The matter is composed of atoms and atom is indivisible particle which can not be destroyed.
2) The atoms of an element are identical.
3) The atoms of different elements are combining with definite proportion and form compounds.
4) The atoms of different elements are different from each other.
5) During chemical reaction rearrangement of atoms occur and form new compounds.
Answer:
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N2 is non polar because electronegative of both the atoms are same and N2 also have linear shape
Enthalpy is the change in energy. A cold pack will react endothermically and enthalpy will be positive and a heat pack will have negative enthalpy. You cannot determine which has more change in enthalpy unless you measure the temperature change. Eg. a heat pack went from 25c to 35c will have greater change in enthalpy then a cold pack going from 25 to 20c because the net temperature difference is greater
Answer:
scientists can only calculate the probability that a significant earthquake will occur in a specific area within a certain number of years.
Explanation:
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