can u help me on these questions?
1) describe the development of the modern periodic table. include contributions made by Lavoiser, Newlands, Mendeleev, and Mosely.
2) describe the general characteristics of metals, nonmetals, and metalloids.
3) identify each of the fallowing as a representative element or a transition element.
(a) lithium---Li
(b) platinum---Pt
(c) promethium---Pm
(d) carbon---C
much help is needed and appriciated
Of course, I'd be happy to help you with these questions!
1) The development of the modern periodic table:
a) Lavoisier: Antoine Lavoisier played a significant role in the development of the periodic table through his work on chemical elements and the concept of chemical reactions. He established the importance of accurately measuring masses of substances and demonstrated that elements cannot be created or destroyed in chemical reactions.
b) Newlands: John Newlands proposed the Law of Octaves in 1863, which arranged the elements into groups of eight. However, his law was limited and did not apply to all elements.
c) Mendeleev: Dmitri Mendeleev is widely recognized as the father of the periodic table. In 1869, he organized the known elements based on their atomic masses and noticed that certain properties recurred periodically. Mendeleev left empty spaces for undiscovered elements and predicted their properties, which were later confirmed when those elements were discovered.
d) Moseley: Henry Moseley's work, published in 1913, led to the realization that the order of elements on the periodic table should be based on their atomic numbers rather than atomic masses. This led to the rearrangement of the table and resolved some inconsistencies.
2) General characteristics of metals, nonmetals, and metalloids:
a) Metals: Metals are generally shiny, conductive (both heat and electricity), and malleable. They tend to form cations (positively charged ions) by losing electrons during chemical reactions and have a lustrous appearance. Metals are found on the left side and the middle of the periodic table.
b) Nonmetals: Nonmetals can be gases, liquids, or brittle solids at room temperature. They are generally poor conductors of heat and electricity. Nonmetals tend to form anions (negatively charged ions) by gaining electrons during chemical reactions. Nonmetals are mainly located on the right side of the periodic table.
c) Metalloids: Metalloids (also known as semimetals) possess properties intermediate between metals and nonmetals. They exhibit characteristics of both groups. Metalloids are located on the staircase line that separates metals from nonmetals on the periodic table.
3) Representative elements and transition elements:
a) Lithium (Li) is a representative element, also known as a main group element. These elements are located in the s-block and p-block of the periodic table.
b) Platinum (Pt) is a transition element, also known as a transition metal. These elements are located in the d-block of the periodic table.
c) Promethium (Pm) is also a transition element, specifically a lanthanide (rare earth) element. Lanthanides are located in the f-block of the periodic table.
d) Carbon (C) is a representative element and is located in the p-block of the periodic table.
I hope this explanation helps you! Let me know if you have any further questions.