Lithium ,sodium and potassium known as alkali metals . which property of the metals is correct? a - strong
b - soft
c - opaque
d - non-lustrous

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

What is happening when the water inside a kettle heats up and begins to boil

What is the most common reason for matter changing its state?