Conduction and convection both require some material substance
to move heat from one place to another, and there's none of that
between the sun and Earth.
The only way for thermal energy to move from place to place with
nothing in between is by the process of radiation, and that's how
it gets here from the sun.
Circuits are also known as current divider circuits because, in these circuits, the current is divided through each resistor. Whereas, series circuits are known as voltage divider circuits because here voltage is divided across all the resistors.
Geologists use the Mohs Harness Scale (aka the Scratch Test) to determine the hardness of a mineral.
For more info, check out http://geology.com/minerals/mohs-hardness-scale.shtml
