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
<u>Answer:</u>
Carbon and silicon both are tetravalent elements as compared to germanium, tin, and lead which are divalent.
That's because Ge, tin, and Pb show inert pair effect and has a greater nuclear effective charge on the 's' electrons due to poor shielding effect. .That's why these elements are not able to share their valence electrons while carbon and silicon does and show "catenation" which is the ability to form long chain molecules.
Answer:
0.8 mol.
Explanation:
- The balanced equation for the reaction between Al and FeO is represented as:
<em>2Al + 3FeO → 3Fe + Al₂O₃,</em>
It is clear that 2 mol of Al react with 3 mol of FeO to produce 3 mol of Fe and 1 mol of Al₂O₃.
<em><u>Using cross multiplication:</u></em>
2 mol of Al needs → 3 mol of FeO, from stichiometry.
??? mol of Al needs → 1.2 mol of FeO.
∴<em> The no. of moles of Al are needed to react completely with 1.2 mol of FeO </em>= (2 mol)(1.2 mol)/(3 mol) = <em>0.8 mol.</em>
The mass number = protons + neutrons. Bromine has a mass number of 80<span> and 35 protons so </span>80<span>-35 = </span>45<span> neutrons. b) How many electrons does the neutral atom of bromine have? The neutral atom of bromine has 35 electrons because the number of electrons equals the number of protons.</span>
Answer:
Mole fraction O₂= 0.43
Explanation:
Mole fraction is the moles of gas/ total moles.
Let's determine the moles of each:
Moles O₂ → 15.1 g / 16 g/mol = 0.94
Moles N₂ → 8.19 g / 14 g/mol = 0.013
Moles H₂ → 2.46 / 2 g/mol = 1.23
Total moles = 2.183
Mole fraction O₂= 0.94 / 2.183 → 0.43
