The mass number of an element is the sum of the number of

An atom is a. the smallest unit of matter that maintains its chemical identity. b. always made of carbon. c. smaller than an electron. d. the smallest unit of a compound.

How many atoms does a molecule of sodium chloride contain?

Whitney's lung capacity was measured as 3.3 l at a body temperature of 37 ∘c and a pressure of 746 mmhg. how many moles of oxygen is in her lungs if air contains 21% oxygen?

Compare How does the current model of the atom differ from J. J. Thomson's model?

What are the different acid bases

What is the molar mass of the following substance : Cs2CO3

What does the velocity of a wave describe

Sulfur (S) has 16 protons and 16 neutrons. How many electron shells does an element of sulfur have?

Which one of the following statements about orbital energies is incorrect? A) The energy of a given orbital increases as the nuclear charge Z increases. B) In many-electron atoms the energy of an orbital depends on both n and l.

When solid lead (II) sulfide ore burns in oxygen gas, the products are solid lead (II) oxide and sulfur dioxide gas.? A. write the balanced equation B. how many grams of oxygen are required to react with 29.9 grams of lead II sulfide? C.