Unit 1

Front

What is a hydrate?

Back

A hydrate is a compound that contains water molecules within its structure, typically represented as a formula like Na2SO4·xH2O, where x indicates the number of water molecules.

Front

How do you calculate the value of x in a hydrate?

Back

To find x, subtract the mass of the anhydrous compound from the mass of the hydrate to find the mass of water lost, then divide by the molar mass of water and the molar mass of the anhydrous compound.

Front

What is the significance of valence electrons in ionic bonding?

Back

Valence electrons are the outermost electrons of an atom and are crucial in forming bonds. Elements with the same number of valence electrons can form ionic compounds in a one-to-one ratio.

Front

What is the photoelectron spectrum?

Back

The photoelectron spectrum is a graphical representation of the energies of electrons emitted from an atom when it is ionized by photons, providing information about the electronic structure of the element.

Front

What does electronic configuration tell us about an element?

Back

Electronic configuration describes the distribution of electrons in an atom's orbitals, which helps predict how the element will react chemically and what compounds it can form.

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Front

How do you determine the formula of a compound formed between two elements?

Back

The formula is determined by the charges of the ions formed by the elements. The total positive charge must balance the total negative charge.

Front

What is the molar mass of a compound?

Back

The molar mass is the mass of one mole of a substance, calculated by summing the atomic masses of all atoms in its chemical formula.

Front

What is the relationship between atomic number and mass number?

Back

The atomic number is the number of protons in an atom, while the mass number is the total number of protons and neutrons. Isotopes have the same atomic number but different mass numbers.

Front

What is the role of sodium in forming ionic compounds?

Back

Sodium (Na) readily loses one electron to form a Na+ ion, allowing it to bond with nonmetals like chlorine (Cl) to form ionic compounds like NaCl.