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
These are discussion questions. We can help review what you write but no one here will write the paper for you.
describe the general characteristics of metals, nonmetals, and metalloids.
Ur black.
Of course, I'll be happy to help you with these questions!
1) The development of the modern periodic table:
- Antoine Lavoisier: Lavoisier is regarded as the "Father of Modern Chemistry." Although he did not directly contribute to the development of the periodic table, his work on chemical reactions and his understanding of the conservation of mass laid the foundation for future discoveries.
- John Newlands: Newlands proposed the Law of Octaves in 1864. He arranged the known elements in increasing atomic weight and noticed that every eighth element had similar properties, suggesting a periodic pattern.
- Dmitri Mendeleev: In 1869, Mendeleev developed the first version of the periodic table. He arranged the elements in order of increasing atomic weight and grouped them based on similar properties. He left gaps in the table for undiscovered elements and accurately predicted their properties.
- Henry Moseley: Moseley's work, around 1913, led to the understanding of atomic numbers and how they were fundamental to the arrangement of elements. He rearranged the elements in the periodic table according to their atomic numbers, providing a more accurate and logical ordering.
2) General characteristics of metals, nonmetals, and metalloids:
- Metals: Metals are generally good conductors of heat and electricity, have a shiny appearance (luster), and are malleable (can be hammered into thin sheets) and ductile (can be drawn into wires). They tend to have high melting and boiling points and are located on the left side of the periodic table.
- Nonmetals: Nonmetals have poor conductivity, both heat and electricity. They often have a dull appearance, are brittle, and can be in solid, liquid, or gaseous forms at room temperature. Nonmetals are primarily found on the right side of the periodic table.
- Metalloids: Metalloids are elements that have properties intermediate between metals and nonmetals. They have partially conductive properties, can be shiny or dull, and may be brittle or malleable. Metalloids are located along a zigzag line on the periodic table, separating metals and nonmetals.
3) Identification of representative and transition elements:
(a) Lithium (Li): Representative element. Representative elements are in groups 1 and 2 and in groups 13-18. Lithium is in Group 1.
(b) Platinum (Pt): Transition element. Transition elements are in groups 3-12, and platinum falls under this category.
(c) Promethium (Pm): Transition element. Promethium is an artificial element, and all elements beyond uranium fall into the transition element category.
(d) Carbon (C): Representative element. Carbon is part of Group 14, which comprises the representative elements.
To answer these questions, I summarized historical contributions, general characteristics, and used the periodic table to identify the element categories. Keep in mind that additional information can be found through further research if needed.