Chemistry: Elements and Compounds Vocabulary

Compendium of practice questions covering molecular definitions, reaction types, diatomic elements, naming conventions for compounds, polyatomic ions, and valencies from the lecture notes.

What does it mean to "synthesize"?

To create.

What is the definition of a molecule according to the notes?

Two or more atoms that are chemically bonded together.

How is a diatomic molecule defined?

A molecule that consists of exactly two atoms (identical atoms).

What is a compound?

A pure substance formed by a chemical reaction between two or more different elements.

What happens during a decomposition reaction?

A chemical reaction in which a compound is broken down into simpler substances or elements.

What is a synthesis reaction?

A process during which two elements combine to form a compound.

What are chemical bonds?

A strong force of attraction that holds atoms together.

What is thermal decomposition?

A chemical reaction in which heat is used to decompose a compound.

Which seven elements are naturally diatomic?

Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, and Bromine.

What mnemonic is used to remember the diatomic elements?

Have No Fear Of Ice Cold Beer ($H_2$, $N_2$, $F_2$, $O_2$, $I_2$, $Cl_2$, $Br_2$).

What criteria can be used to distinguish a compound from an element based on its chemical symbol?

If it has more than one capital letter, it is a compound.

What two things does a specific chemical formula show for a pure substance?

Which elements it contains and the ratios of the elements to each other.

In the formula for chalk, $\text{CaCO}_3$, what is the ratio of Calcium to Carbon to Oxygen atoms?

$$1:1:3$$

When naming a compound made of a metal and a non-metal, how is the second element's name changed?

The name of the second element must end in "-ide" (e.g., chlorine becomes chloride).

What prefixes are used for the second element when naming compounds made of two non-metals?

mono (1), di (2), tri (3), tetra (4), pent (5), hex (6), and hept (7).

What is the name of the compound $P_2O_5$?

Phosphorus pentoxide.

What is the name of the polyatomic ion $\text{NO}_3^-$?

Nitrate

What is the name of the polyatomic ion $\text{SO}_4^{2-}$?

Sulfate (or Sulphate)

What is the name of the polyatomic ion $\text{CO}_3^{2-}$?

Carbonate

What is the name of the polyatomic ion $\text{OH}^-$?

Hydroxide

What is the name of the polyatomic ion $\text{NH}_4^+$?

Ammonium

What is the name of the polyatomic ion $\text{PO}_4^{3-}$?

Phosphate

What is the definition of "valency"?

The number of bonds which an atom can form.

What is the typical charge and valency of elements in Group 1?

Charge: $+1$; Valency: $1$

What is the typical charge and valency of elements in Group 17?

Charge: $-1$; Valency: $1$

What is the typical valency of Transition metals (except Silver)?

$2$ (Silver/Ag is $1$).