Societies have changed over time, and consequently, so has science. For example, during the first half of the 20th century, when the world was enmeshed in war, governments made funds available for scientists to pursue research with wartime applications — and so science progressed in that direction, unlocking the mysteries of nuclear energy. At other times, market forces have led to scientific advances. For example, modern corporations looking for income through medical treatment, drug production, and agriculture, have increasingly devoted resources to biotechnology research, yielding breakthroughs in genomic sequencing and genetic engineering. And on the flipside, modern foundations funded by the financial success of individuals may invest their money in ventures that they deem to be socially responsible, encouraging research on topics like renewable energy technologies. Science is not static; it changes over time, reflecting shifts in the larger societies in which it is embedded
Answer : The correct option is A.
Explanation :
Metalloid : Metaloids are the elements whose properties lie between the metals and non-metals.
There are six commonly elements which are boron, silicon, germanium, arsenic, antimony and tellurium. The rare elements are polonium and astatine.
The relation between the group number and period number of metalloid is that the lower the group number, the lower the period numbers and the metalloids are found in a diagonal moving down from left to right in the periodic table.
Answer: 1.36 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
where,
n = moles of solute
To calculate the moles, we use the equation:
moles of solute= 
The balanced reaction between barium hydroxide and perchloric acid:
To calculate the concentration of acid, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is 
We are given:
Putting values in above equation, we get:
Thus the concentration of the acid is 1.36 M
Answer:
Ammonia is easily made in the laboratory by heating an ammonium salt, such as ammonium chloride NH4Cl with a strong alkali, such as sodium hydroxide or calcium hydroxide.
The gas may also be made by warming concentrated ammonium hydroxide.
Explanation:
2NH4Cl + Ca(OH)2 → CaCl2 + 2H2O + 2NH3(g)
The answer is 3. The releasing of energy means exothermic reaction. So the ΔH should be negative. And the greatest quantity of energy released means that the greatest number. So according to the table I, the answer is 3.
