Criado por Ahmed Almohammed
mais de 8 anos atrás
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Questão | Responda |
What are atoms? | Atoms are the building blocks of every substance in the universe. |
What are elements? and how many atoms are in an element? | Elements are the most basic materials for building the world.Elements are substances that are made up of only one atom. |
What is an STM and what does it stand for? | Scanning Tunnelling Microscope is the only type of microscope powerful enough to obtain images of atoms. |
What are the two types that elements classified into? | Metallic and non-metallic elements |
What are some metallic elements properties? | |
What are some non-metallic elements properties? | -Not shiny -Do not conduct heat or electricity -Break when you bend them -Non-metals often referred to as being Brittle |
How many elements are known? and how many of them occur naturally? | There are 118 known elements, but only 91 of them occur naturally. |
What are the three different ways in which atoms are arranged in Elements? | -Single atoms (Monatomic) -Cluster of atoms (Molecules) -large grid(Lattices) |
What is a Monatomic? | An element that consists of just single atoms |
What are the six of the 92 naturally occurring elements being monatomic and also non-metallic? | These 6 are helium,neon,argon,krypton,xenon and radon |
What are Molecules? | Molecules are clusters of two or more atoms bonded or joined together |
Why is it that some elements have a molecular formula such as <--------------- | It's because molecular formulas show what atoms are in a molecule and how many there are of each. for example, O2 shows that each oxygen molecule has two oxygen atoms. |
What is Carbon and what is the most famous type? | Carbon is unique among the non-metallic elements in that it can form very large molecules of almost any size. The most famous type is buckyball. |
What percentage of the known elements is metal? | 80% |
What are lattices and what does this structure do? | Lattices are large grid-like structures, this structure makes metals strong and solid at room temperature. |
What happens in metal lattices? | In metal lattices, the atoms are only weakly joined to each other.As a result, metals can be bent and drawn into wires. |
What are the two types of carbon that form lattices? | Diamond & Graphite |
Why is it that Diamond is the hardest natural substance? | In Diamond, the carbon atoms are bonded strongly to each other in four directions. |
What happens in non-metallic lattices? | In non-metallic lattices, the atoms are strongly bonded to each other.This makes them hard to brittle. |
What are allotropes? and what are the allotropes of carbon? | Allotropes are different forms of the same element.The following are the allotropes of Carbon-: 1-Charcoal 2-Graphite 3-Diamond 4-Carbon fibre 5-Buckyballs and nanotubes |
What is Charcoal used for? | Charcoal has many beneficial uses such as in the use of sketching, in the process of smelting iron, used as tablets and gas filter in gas masks. |
Graphite? | In graphite, the atoms bond together in sheets that can slide over one another.This makes graphite a good lubricant. |
Diamond? | Carbon in the form of diamond is the hardest substance on earth because the bonds between the carbon atoms are extremely strong. |
Carbon fibre? | Carbon fibre is very light , very strong and flexible and so is often used in sporting equipment such as bike frames. |
Buckyballs and nanotubes? | Buckyballs are balls of 60 carbon atoms that have the same geometric shape as the soccer ball. The discovery of the buckyball led to the development of nanotubes. Nanotubes are a form of carbon that can be thought of as a sheet of carbon rolled into a tube. |
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