Answer:
76
Explanation:
Alpha decay is one of the most basic forms of radioactive decay. It has an atomic mass of 4 and a proton number of two.
Undergoing an alpha decay will decrease the atomic mass by four and the atomic number by two.
In this particular question, we are particular about the atomic number. The atom has an atomic number of 78. So taking 2 off this gives 76
Answer: B
Explanation:
There is an atom of one type of element and then two atoms of another type of element.
Answer:
B. They oxidize hydrocarbons to form less toxic gases.
Explanation:
A catalytic converter can be defined as an anti-pollution device containing a catalyst like platinum-iridium, installed in the exhaust chamber of an automobile so as to chemically convert harmful (poisonous) pollutants such as unburned hydrocarbons and carbon monoxide (CO), sulfur dioxide (S02), nitrogen oxide (NO) etc., into less harmful, poisonous or toxic chemical compounds.
This ultimately implies that, catalytic converters are typically used for converting harmful gases into less harmful, poisonous or toxic gases and molecules e.g carbon dioxide (C02) and water (H2O). This helps to prevent global warming, enhance the conservation of natural resources, as well as preserve the lives of living organisms and their natural habitat.
<em>Hence, the statement which best describes the use of catalytic converters in automobiles is that they oxidize hydrocarbons to form less toxic gases.</em>
Answer:
0.17325 moles per liter per second
Explanation:
For a first order reaction;
in[A] = in[A]o - kt
Where;
[A]= concentration at time t
[A]o = initial concentration
k= rate constant
t= time taken
ln0.5 =ln1 - 2k
2k = ln1 - ln0.5
k= ln1 - ln0.5/2
k= 0 -(0.693)/2
k= 0.693/2
k= 0.3465 s-1
Rate of reaction = k[A]
Rate = 0.3465 s-1 × 0.50 mol/L
Rate = 0.17325 moles per liter per second
