If an atom has an atomic mass of 24 and its atomic number is 11, how many protons will

it have? Electrons? Neutrons?

How did Mendeleev arrange the known elements in his periodic table?

K20 ionic or covalent

What gas is produced when calcium metal is dropped in water

Perspiration is 50 percent water, 25 percent salt, and 25 percent organic materials. true or false

Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after increasing the pressure. N2 (g) + 3H2 (g) 2NH3 (g) The concentration of N2 will (A) stay the same. (B) decrease. (C) increase.

A) What are the postulates of Bohr's model of an atom? (b) Show diagrammatically the electron distributions in Sodium, Lithium and Aluminium atoms

How many liters of air are in a room that measures 10.0 ft * 11.0 ft and has an 8.00 ft ceiling? 1 in. = 2.54 cm (exactly); 1 L = 103 cm3

Which of these represents a chemical change? A) two compounds combining to form a mixture B) a mixture being separated into two elements C) a compound being separated into two elements D) an element changing state from solid to liquid

What properties would have caused early researchers to name hydrogen "inflammable air"

Enter the symbol of a sodium ion, Na+, followed by the formula of a sulfate ion, SO42-