3.Write the symbol of the element that has a charge of +1 when it has 71 electrons.
1 answer:
The symbol :
There are two components that accompany an element, the mass number and atomic number
Atoms are composed of 3 types of basic particles (subatomic particles): <em>protons, electrons, and neutrons </em>
The Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.
Atomic number = number of protons = number of electrons ⇒ neutral number
Atomic mass is the sum of protons and neutrons
Atomic Number (Z) = Atomic mass (A) - Number of Neutrons
The element has 71 electrons and a charge of +1 , so
Number of protons = 71 + 1 = 72
Number of protons = the atomic number = 72
The element with atomic number 72 is Hafnium(Hf)
The atomic mass of Hf = 178 g/mol
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Answer:
2.943 °C temperature change from the combustion of the glucose has been taken place.
Explanation:
Heat released on combustion of Benzoic acid; :
Enthaply of combustion of benzoic acid = 3,228 kJ/mol
Mass of benzoic acid = 0.590 g
Moles of benzoic acid =
Energy released by 0.004831 moles of benzoic acid on combustion:
Heat capacity of the calorimeter = C
Change in temperature of the calorimeter = ΔT = 2.125°C
Heat released on combustion of Glucose: :
Enthaply of combustion of glucose= 2,780 kJ/mol.
Mass of glucose=1.400 g
Moles of glucose =
Energy released by the 0.007771 moles of calorimeter combustion:
Heat capacity of the calorimeter = C (calculated above)
Change in temperature of the calorimeter on combustion of glucose = ΔT'
2.943 °C temperature change from the combustion of the glucose has been taken place.