The elements are placed in specific places on the periodic table based on their atomic number and outer electronic configuration which gives them certain properties.
The elements of same groups have same number of valence electrons.
Group 1: one electron in valence shell
Group 2: two electrons in valence shell.
Helium has only two electrons in its outer shell and it is grouped with elements that have completely filled outer orbitals, noble gas.
Answer:
1008.0 kJ.
Explanation:
- Firstly, we need to calculate the no. of moles of 88.0 g of propane:
<em>n = mass/molar mass </em>= (88.0 g)(/(44.0 g/mol) = <em>2.0 mol.</em>
∴ The combustion of 2.0 moles of propane produces 4032.0 kJ.
<em><u>Using cross multiplication: </u></em>
The combustion of 2.0 moles of propane produces → 4032.0 kJ.
The combustion of 0.5 moles of propane produces → ??? kJ.
<em>∴ The amount of heat released for the combustion of 0.5 moles of propane </em>= (4032.0 kJ)(0.5 mol)/(2.0 mol) = <em>1008.0 kJ.</em>
1840 times lesser than
Explanation:
Robert A. Milikan from his experiment found that electrons carry exactly one unit of negative charge and that its mass is 1840 times lesser than the mass of a common hydrogen atom.
- Robert Milikan performed the oil drop experiment and was able to determine the charge on an electron.
- From Milikan's experiment, the relative mass of an electron was discovered to be about 1840 times lesser than the mass of a hydrogen atom.
- A normal hydrogen atom is a proton with an actual mass of 1.67 x 10⁻²⁷kg.
- Electrons weight 9.11 x 10⁻³¹kg which is 1840 less than the weight of a proton.
Learn more:
electrons brainly.com/question/10887448
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N(Mg) : n(O)
1 : 1
the ratio is one to one
