Answer: n= 3, l= 0 , m= 0 and s=[/tex]\frac{-1}{2}[/tex]
Explanation:
Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....
Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...
Magnetic quantum number : It describes the orientation of the orbital. It is represented as 'm'. The value of m ranges from -l to +l.
Spin quantum number: It describes the spin of the electron. It is represented as 's'. The value of s can be +1/2 or -1/2
Thus electron enters 3s orbital , thus n= 3, l= 0 , m= 0 and s=[/tex]\frac{-1}{2}[/tex]
Solve first for the number of moles of sodium given that the mass is 2500 g by dividing the given mass by the molar mass of sodium.
moles sodium = 2500 g / 23 g/mol
moles sodium = 108.7 moles
Since in every mole of NaCl, there is only one mole of sodium then, we conclude that there are also 108.7 moles of NaCl. Multiplying the number of moles to the molar mass of sodium chloride (58.44), the answer would be 6,352.17 grams.
i will ans the 2nd part first:
heat sources 4 homes: those wuld be renewable resources that generate heat. They include geothermal, solar water-heating and bio-mass.
primarily produce electricity: those wuld be something that is big like a dam for hydroelectric, wind turbine for electric generation, and solar farm for electricity.
Answer:
- <em><u>Mendeleev produced the first orderly arrangement of known elements.</u></em>
- <em><u>Mendeleev used patterns to predict undiscovered elements.</u></em>
Explanation:
- <u>Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.</u>
Those two statments are true.
For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.
More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).
The first modern chemistry book was written by Antoine Lavoisier (this discards first option).
Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).
Isotopes were not known by Mendeleev times, so this discards the last option.
Scale and measuring tape.
To determine the mass and volume, you can find the density. The block will float if its density is less than that of water.
