Answer:
Speed
Explanation:
Aliyah must have been trying to find her speed.
The speed is a measure of how fast an object or a body is and it is calculated by finding the ratio of distance with time. Mathematically,
speed = 
with a unit of m/s.
<em>Hence, with the distance measured on the ground and Aliyah trying to find the time it will take her to cover the distance while running, she must have been trying to find how fast she can run, that is, speed. </em>
Answer:
substances with a higher boiling point are returning back to the flask which allows another substances with the specific context temperature (lower boiling point) to boil over and be purified.
Explanation:
The reason it happens because the lower boiling point substance vaporizes and crosses over while the other substance is waiting for its boiling point to reach
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.
Answer:
0.143L
Explanation:
Molar mass of H2SO4 = 98g/Mol
No of mole = mass/molar mass
No of mole= 49/98 = 0.5 mol
No of mol = concentration × volume
Volume = n/C = 0.5/3.5 = 0.143L
Answer:
hello hope this helps :)
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
