Questions

Hub works on layer 1 i.e, physical layer.

A seconds pendulum is a pendulum whose period is precisely two seconds i.e, one second for a swing in one direction and one second for the return swing.

Heat from the sun travels in the form of rays and are called as heat rays. This heat is called as radiation.

The memory which can be retained even the power is off is called as Permanent memory or Persistent memory. Computer's hard drive is an example of permanent memory and computer's cache or RAM are examples of temporary memory.

Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate) is the inorganic compound with the chemical formula KHCO3. It is a white solid

Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder.

LiHCO3 is found in solution form while rest alkali metals hydrogen carbonates are solid due to the anomalous properties of Li and its diagonal relationship with the Mg.