Answer:
a. True
Explanation:
In the periodic table , all the elements are placed in a certain fashion , i.e. , with increasing atomic number.
Since ,
The element lithium and nitrogen are placed , in group 1 and 15 respectively.
as we go from left to right , across the group , the atomic radius decreases ,
Because ,
As , we go left to right , the number of electrons increases in the same shell , and proton too increases , which in turn increases the nuclear attraction , and the nucleus holds on to the electrons more firmly , and hence , the size reduces , as the electrons increases , in the same shell.
Hence, the given statement is true.
The axon is a thin fiber that carries signals away from the cell body.
Answer:
See image attached and explanation
Explanation:
The stratospheric ozone layer is very important in absorbing high-energy ultraviolet radiation that is harmful to living systems on earth. The concentration of ozone in the stratosphere is determined by both thermal and photochemical pathways for its decomposition. Nitric oxide, NO, is a trace constituent in the stratosphere that reacts with ozone to form nitrogen dioxide, NO2, and the diatomic oxygen molecule. The nitrogen-oxygen bond in NO2 is relatively weak. When an NO2 molecule encounters an oxygen atom, it transfers an oxygen, forming O2 and NO. The chemical reactions involved are formations of NO2 following by reaction of NO2 with atomic oxygen for form NO and O2. The sum of both reactions show that the overall reaction is simply the reaction of ozone with atomic oxygen to form two molecules of molecular oxygen. Hence, NO only serves as a catalyst, it does not undergo a permanent change itself.
Answer:
D. 0.543kg of copper metal is produced from 0.680kg of copper 1 sulphide.
Explanation:
First write the equation for the reaction:
Cu2S + O2 ------> 2Cu + SO2
Determine the mole ratio of the two substances:
I mole of Cu2O forms 2 moles of Copper metal
The number of moles of copper 1 sulphide used is;
n = mass of Cu2S / molar mass of Cu2S
Mass = 0.680kg = 680g
Molar mass = 159.16g/mol
n = 680g / 159.16g/mol
n = 4.272moles
Determine the number of mole of copper:
Number of moles of copper metal produced from 4.272moles of copper 1 sulphide is therefore:
n of copper = 2 * 4.272 Moles
n = 8.544moles.
Determine the mass copper:
The mass of copper metal produced is therefore = number of moles of copper * molar mass of copper
mass = 8.544 moles * 63.55g/mol
mass = 542.97grams
Mass = 0.543kg
