B. 7.5
C. 15
D. 30
The answer is D. 30 percent
b. Pyrite
c. Quartz
d. Calcite
Answer:
5 significant figures
Explanation:
The symbol of an isotope that atom of its element contains 50 electrons and 70 neutrons is Tin (Sn).
The Isotope may be characterized as one of two or more types of atoms of a chemical element that significantly have the same number of protons but with different numbers of neutrons and therefore different atomic masses.
In a more simple sense, an isotope may be defined as an atom that has the same atomic number but different atomic mass and physical properties.
According to the question,
The number of electrons an atom possesses = 50.
The number of neutrons = 70.
Since, the number of electrons = the number of protons = the atomic mass of an atom = 50.
∴ According to the periodic table, an element having an atomic number of 50 is known as Tin (Sn).
Its atomic mass = the number of protons + the number of neutrons.
= 50 + 70 = 120 amu.
Therefore, the symbol of an isotope that the atom of its element contains 50 electrons and 70 neutrons is Tin (Sn).
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The reactant surface area increases.
The reaction rate decreases.
The reaction is not affected at all.
The reaction stops completely.
Answer:
The increase in pressure alters the equilibrium of the reaction. In this case, the number of gaseous products in the reactant side is zero while the product side contains 1 gaseous product. The increase in pressure favors the side with less number of gaseous molecules which is the reactant side. Hence, the reaction rate decreases.
Explanation:
(2) 2H2O(l) + energy → 2H2(g) + O2(g)
(3) H2O(l) → H2O(s) + energy
(4) H2O(g) → H2O(l) + energy
The answer is B because energy was added to 2H2O in order to produce a chemical change of 2H2 and 02 seperately.
The balanced equation that represents a chemical change is 2H2O(l) + energy → 2H2(g) + O2(g).
The balanced equation that represents a chemical change is (2) 2H2O(l) + energy → 2H2(g) + O2(g). In this equation, we see the reactant, water (H2O), being converted into two separate products, hydrogen gas (H2) and oxygen gas (O2), with the addition of energy. This indicates a chemical change taking place where new substances are formed.
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