Answer:
As a substance melts, and goes from a solid to a liquid state, the kinetic energy of the molecules increases, and the molecules move faster, and they separate further and further away from each other. The intermolecluar forces holding the molecules together become weaker. This is why a liquid can take fill the shape of its container, whereas a solid has a fixed shape.
Explanation:
take your notes man
The mass percentage of Na in NaCl is 39.0%
This means that if there's 100 mg of NaCl , 39 mg of the compound is Na.
For compound to contain 39 mg Na - 100 mg of NaCl should be present.
Therefore for the compound to contain 400 mg - 100/39 x 400 - 1025.6 mg
The mass of NaCl present should be 1.026 g
John Dobereiner proposed the idea of similarity in the properties of elements which can be placed together.
He proposed the idea of classification so that we can study the properties of a group of elements together
According to him, three elements can be grouped based on their similarities in properties. This group of three elements was termed as "Triads"
For example :
Li, Na, K
Now the significance of the triad was that the atomic weight of middle element is average of atomic weights of the side atoms
So atomic weight of Na = 23 is average of atomic weights of Lithium and Potassium
7 + 39/2 = 46/2= 23
The other triads were
Ca Sr Ba
Cl Br I
S Se Te
Answer:
A. Chlorine
Explanation:
Chlorine has 17, Hydrogen has 1, Oxygen has 8, Sulfur has 16.
