How are coal types classified? color and texture
carbon content and heat value
depth from the surface
sulfur content

Aseries circuit contains a 30 e resistor, a 20 resistor, and a 10 resistor. the power supply provides 100 v to the circuit the current in the 10 resistor, to two significant figures, is a.

What belongs in the areas marked x and y? x: the internal energy of a piston system increases as heat is added and rises to a cool area y: as thermal energy is added to a container, some of the energy is lost to the environment x: as thermal energy is added to a container, some of the energy is lost to the environment y: the internal energy of a piston system increases as heat is added and rises to a cool area x: a cold spoon placed in hot liquid gets warmer y: thermal energy is converted to light energy x: thermal energy is converted to light energy y: a cold spoon placed in hot liquid gets warmer

When thorium (90 protons) ejects a beta particle, the resulting nucleus has question 18 options: 87 protons. 88 protons. 89 protons. 90 protons. none of the above