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raketka [301]
2 years ago
6

_____________________ held that all matter is made up of four “elements”— earth, air, fire, and water.

Chemistry
1 answer:
Novosadov [1.4K]2 years ago
4 0

Answer:

Democritus

Explanation:

He spoke about matter was made of tiny particles which moved in empty space

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Determine the elements present in sodium hydrogen carbonate ​
Ilia_Sergeevich [38]

Sodium, hydrogen, carbon, and oxygen

6 0
2 years ago
Combustion analysis of toluene, a common organic solvent, gives 3.52 mg of co2 and 0.822 mg of h2o. if the compound contains onl
IRISSAK [1]
<span>C7H8 First, lookup the atomic weight of all involved elements Atomic weight of carbon = 12.0107 Atomic weight of hydrogen = 1.00794 Atomic weight of oxygen = 15.999 Then calculate the molar masses of CO2 and H2O Molar mass CO2 = 12.0107 + 2 * 15.999 = 44.0087 g/mol Molar mass H2O = 2 * 1.00794 + 15.999 = 18.01488 g/mol Now calculate the number of moles of each product obtained Note: Not interested in the absolute number of moles, just the relative ratios. So not going to get pedantic about the masses involved being mg and converting them to grams. As long as I'm using the same magnitude units in the same places for the calculations, I'm OK. moles CO2 = 3.52 / 44.0087 = 0.079984 moles H2O = 0.822 / 18.01488 = 0.045629 Since each CO2 molecule has 1 carbon atom, I can use the same number for the relative moles of carbon. However, since each H2O molecule has 2 hydrogen atoms, I need to double that number to get the relative number of moles for hydrogen. moles C = 0.079984 moles H = 0.045629 * 2 = 0.091258 So we have a ratio of 0.079984 : 0.091258 for carbon and hydrogen. We need to convert that to a ratio of small integers. First divide both numbers by 0.079984 (selected since it's the smallest), getting 1: 1.140953 The 1 for carbon looks good. But the 1.140953 for hydrogen isn't close to an integer. So let's multiply the ratio by 1, 2, 3, 4, ..., etc and see what each new ratio looks like (Effectively seeing what 1, 2, 3, 4, etc carbons look like) 1 ( 1 : 1.140953) = 1 : 1.140953 2 ( 1 : 1.140953) = 2 : 2.281906 3 ( 1 : 1.140953) = 3 : 3.422859 4 ( 1 : 1.140953) = 4 : 4.563812 5 ( 1 : 1.140953) = 5 : 5.704765 6 ( 1 : 1.140953) = 6 : 6.845718 7 ( 1 : 1.140953) = 7 : 7.986671 8 ( 1 : 1.140953) = 8 : 9.127624 That 7.986671 in row 7 looks extremely close to 8. I doubt I'd get much closer unless I go to extremely high integers. So it looks like the empirical formula for toluene is C7H8</span>
7 0
3 years ago
Define the term macromolecule
makkiz [27]

Explanation:

a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.

4 0
2 years ago
A gas occupies 12.3 litres at pressure of 40 cm of Hg. What is the volume in ml when the pressure is increased to 600 mm of Hg a
aalyn [17]

Answer:

Good Luck!

Explanation:

4 0
2 years ago
An orbital of an atom is defined as the most probable location of(1) an electron (2) a neutron (3) a positron (4) a proton
Montano1993 [528]

Answer: option (1) an electron.


Justification:


1) The plum pudding model of the atom conceived by the scientist J.J. Thompson, described the atom as a solid sphere positively charged with the electrons (particles negatively charged) embedded.


2) The next model of the atom, developed by the scientist Ernest Rutherford, depicted the atom a mostly empty space with a small dense positively charged nucleous and the electrons surrounding it.


3) Then, Niels Bhor came out with the model of electrons in fixed orbits around the nucleous, just like the planets orbit the Sun. So, the path followed by the electrons were orbits.


4) The quantum model of the atom did not place the electrons in fixed orbits around the nucleous but in regions around the nucleous. Those regions were named orbitals. And they are regions were it is most probable to find the electron, since it is not possible to tell the exact position of an electron.


As per this model, the electron has a wave function associated. The scientist Schrodinger developed the wave equation which predicts the location of the electron as a probability.


The orbitals are those regions were it is most likely to find the electron. Those regions are thought as clouds of electrons.

5 0
3 years ago
Read 2 more answers
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