Whenever a variable is defined outside of the module environment, its name is stored in the global symbol table. Whenever you are programming in immediate mode outside of a module, you are working ...

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

The periodic table stares down from the walls of just about every chemistry lab. The credit for its creation generally goes to Dimitri Mendeleev, a Russian chemist who in 1869 wrote out the known ...

Symbol equations are a quick way of representing chemical reactions. They show us what atoms are involved and how they are bonded together. Symbol equations always take the form, reactants → products.

Play this game to learn about lots of different elements in the periodic table. While you're watching, look out for where different elements are found in the periodic table. Mrs Roberts: So, here I ...

When the macro processor executes a macro program statement that can create a macro variable (such as a %LET statement), the macro processor attempts to change the value of an existing macro variable ...