Each substance has a unique set of properties that depends on the kinds of atoms it has and how the atoms are connected, or bonded. Bonding is related to the electrons in an atom, and there are different kinds of bonds. As a result, some substances can have the same atoms but different bonds. Substances that are different but have the same atoms are called allotropes. Allotropes have very different properties. Diamond and graphite are well-known allotropes. Graphite is used in pencils for writing and is sometimes called lead. Diamond is colorless and transparent, and is one of the hardest substances known. Graphite is dark gray and soft. When we write, layers of graphite easily transfer from the pencil to the paper. Although they’re different, diamond and graphite each only contain one kind of atom—carbon.

How do you think the bonds between carbon atoms might be different in diamond and graphite? Use household materials to build physical models to help you develop your ideas. Describe what you learned from your models. What other kinds of allotropes are there? What kinds of properties and atomic bonds do they have?

Over the last several years, india’s taxi wars have been limited to two players, uber and ola, which together hold nearly 95% of the market. one of the major challenges that uber faces in major cities, india unlike anywhere else is the competition/threats from taxi drivers and auto-rikshaw drivers alike. uber is much safer and also cheaper. it is a lot cheaper than the other taxi drivers/cab companies and auto drivers trying to scam you in terms of money. on the application of ubber show the message " first take left, then second right, drive for 100 meters and wait outside the coffee coloured building to your right." it is extremely difficult to believe that the app which relies on gps positioning for drivers and customers to find each other often fails in india. uber operates in 58 markets but india is the only country where the card-only mode of payment just never kicked off. among several reasons - the internet connectivity, the two step verification system with cards dealt the final blow. in most markets, the amount gets deducted from your saved credit card information. but in india, there is another verification step of punching in a unique code or one-time password sent to the mobile phone. in this context, find out the following issues: define the problems in this case. analysis of situation in ride sharing economy. what are the possible solutions for this case? what are the way forwards to move new digital disruption cases?