Answer:
A boundary is a real or imaginary line that separates two things. In geography, boundaries separate different regions of the Earth.The most obvious type of boundary is a physical boundary. A physical boundary is a naturally occurring barrier between two areas. Rivers, mountain ranges, oceans, and deserts can all serve as physical boundaries. Many times, political boundaries between countries or states form along physical boundaries. For example, the boundary between France and Spain follows the peaks of the Pyrenees Mountains, while the Alps separate France from Italy.
The Strait of Gibraltar is the boundary between southwestern Europe and northwestern Africa. This narrow waterway between the Atlantic Ocean and the Mediterranean Sea is an important political, economic, and social boundary between the continents.
Rivers are common boundaries between nations, states, and smaller political units such as counties. The Rio Grande forms a large part of the boundary between Mexico and the United States. The Mississippi Riveris the defining boundary between many of the states it winds through, including Iowa and Illinois, Arkansas and Tennessee, and Louisiana and Mississippi.
Answer:
588.2 mL
Explanation:
- FeSO₄(aq) + 2KOH(aq) → Fe(OH)₂(s) + K₂SO₄(aq)
First we <u>calculate how many Fe⁺² moles reacted</u>, using the given <em>concentration and volume of FeSO₄ solution</em> (the number of FeSO₄ moles is equal to the number of Fe⁺² moles):
- moles = molarity * volume
- 187 mL * 0.692 M = 129.404 mmol Fe⁺²
Then we convert Fe⁺² moles to KOH moles, using the stoichiometric ratios:
- 129.404 mmol Fe⁺² *
= 258.808 mmol KOH
Finally we<u> calculate the required volume of KOH solution</u>, using <em>the given concentration and the calculated moles</em>:
- volume = moles / molarity
- 258.808 mmol KOH / 0.440 M = 588.2 mL
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.
The correct answer is the second option. Particulate matter is the air pollutant known to affect people with asthma. It also can cause other illnesses like cough, chest discomfort and a burning sensation in the lungs.
