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.
In a simple distillation setup, the sequence of equipment from the bench top to the round bottom flask is:
- Thermometer
- Distillation flask
- Round bottom flask
- Bunsen burner
<h3>What is Distillation?</h3>
This is the process in which a mixture is separated through selective boiling and condensation.
The distillation flask and liebig condenser are usually located above the round bottom flask in the set up.
Read more about Distillation here brainly.com/question/24553469
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Answer:
Explanation:
mole of O₂ = 
= .25 moles
mole of CO₂
= 
= .1818 moles
moles of SO₂

= .125 moles
Total moles of gas
= .5568 moles.
total volume of gas mixture
= 22.4 x .5568 liter ( volume of one mole of any gas = 22.4 liter)
= 12.47 liter.
gas will exert partial pressure according to their mole fraction
gas having greatest no of moles in the total mole will have greatest mole fraction so
O₂ will have greatest partial pressure.
Answer:
464.1 J absorbed.
Explanation:
Given data:
Specific heat of zinc = 0.39 J/g°C
Mass of zinc = 34 g
Temperature changes = 22°C to 57°C
Energy absorbed or released = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 57°C - 22°C
ΔT = 35°C
Q = m.c. ΔT
Q = 34 g. 0.39 J/g°C. 35°C
Q = 464.1 J
The energy increases because the molecules in water move faster