One of the most convenient ways of finding or calculating for the
midpoint of the line segment is to get the average of the coordinates of the
points.
Average of abscissa = (0 + 0) / 2 = 0
Average of ordinate = (0 + 15) / 2 = 7.5
Hence, the midpoint of the line segment is equal to (0, 15/2).
The value of the y-intercept is 15/2.
Answer:
<h3>The answer is 8.00 moles</h3>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>8.00 moles</h3>
Hope this helps you
Proton number = the atomic number (which is the smaller number
neutron number = the mass number (the bigger number) - the atomic number
number of electrons = the atomic number - the charge (it depends on the element but group 1 is +1 group 2 is +2 group 3 is +3 group five is -3 group six is -2 group seven is -1
i would solve the whole thing but its unclear hope this helps tho
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.
Exothermic.
To remember this, ‘exo’ means outside, and ‘thermic’ means heat. It gives the outside (exo), heat (thermic).
