Answer:
The periodic table has gone through many changes since Dmitri Mendeleev drew up its original design in 1869, yet both the first table and the modern periodic table are important for the same reason: The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its location on the table
Explanation:
hope it helps you
Answer:
(C) through the atmosphere
Explanation:
Answer:
Work done, W = 128 kJ
Explanation:
Given that,
Weight of a mountain climber, F = 800 N
It climbs to a cliff that is 160 m high.
We need to find the work done by the mountain climber. The work done by an object is given by the formula as follows :
W = Fd
Put the values of F and d.
W = 800 N × 160 m
W = 128000 J
or
W = 128 kJ
So, 128 kJ of work is done by the mountain climber.
The given statement, some type of path is necessary to join both half-cells in order for electron flow to occur, is true.
Explanation:
Flow of electrons is possible with the help of a conducting medium like metal wire.
A laboratory device which helps in completion of oxidation and reduction-half reactions of a galvanic or voltaic cell is known as salt bridge. Basically, this salt bridge helps in the flow of electrons from anode to cathode and vice-versa.
If salt bridge is not present in an electrochemical cell, the electron neutrality will not be maintained and hence, flow of electrons will not take place.
Thus, we can conclude that the statement some type of path is necessary to join both half-cells in order for electron flow to occur, is true.
Answer:
The correct option is: c. 15
Explanation:
Phosphorous is a chemical element which belongs to the group 15 of the periodic table and has atomic number 15. It is a highly reactive non-metal of the p-group.
Since, atomic number of an atom is the number of electrons and number of protons for neutral atoms.
So, the number of protons = number of electrons = 15
The atomic mass is obtained by adding the number of neutrons and the protons.
So, number of neutrons + number of protons = 30
So, number of neutrons + 15 = 30
Therefore, the number of neutrons in ³⁰P = 15
