quiz 2 stuff for chmistry

These flashcards cover important definitions and concepts from atomic theory and structure, as discussed in the lecture.

What is the Law of Conservation of Mass?

Matter cannot be created or destroyed in chemical reactions.

What are the key early atomic laws?

The Laws of Conservation of Mass, Definite Proportions, and Multiple Proportions.

What does Dalton’s Atomic Theory say?

Everything is made of tiny particles called atoms. Atoms of the same type are the same, and compounds are made in whole-number ratios.

What did Thomson discover?

He discovered electrons using a cathode ray experiment.

What did Millikan discover?

He found the charge of the electron using an oil-drop experiment.

What did Rutherford discover?

He discovered the nucleus of the atom, showing that atoms are mostly empty space.

What does the atomic number represent?

It shows how many protons are in an atom.

What does the mass number tell us?

It is the total number of protons and neutrons in an atom.

What are isotopes?

Atoms that are the same element but have different numbers of neutrons.

What are ions?

Atoms that have a charge because they gained or lost electrons.

What is an empirical formula?

It shows the simplest whole-number ratio of atoms in a compound.

What is a molecular formula?

It shows the actual number of each type of atom in a molecule.

How do you count atoms in a formula?

You look at the subscripts (like in H2O, there are 2 hydrogen atoms and 1 oxygen atom).

What are groups on the periodic table?

The vertical columns that contain similar elements, like alkali metals.

What are periods on the periodic table?

The horizontal rows that represent energy levels of electrons.

What are categories on the periodic table?

The different types of elements, such as metals, nonmetals, and metalloids.

What are ionic compounds?

Compounds made from the transfer of electrons between metals and nonmetals.

What are covalent compounds?

Compounds made from sharing electrons between nonmetals.

What are diatomic elements?

Elements that exist naturally as pairs, like H2 and O2.

What is an Isotope?

Isotopes are different forms of an element that have the same number of protons but a different number of neutrons. This means they have different masses, but they behave similarly in chemical reactions

What does Mass Number refer to?

Total count of protons and neutrons in an atom.

What defines the Atomic Number

Number of protons in an atom.

What are Transition Metals?

Elements in the bottom section of the periodic table, typically with variable oxidation states.

What are Ionic Compounds?

Compounds formed by the reaction of metals and nonmetals that result in the transfer of electrons.

How are Covalent Compounds formed?

Compounds formed by the sharing of electrons between nonmetals.

Where can Metals be found on the periodic table?

Elements found on the left side of the periodic table that conduct electricity and heat.

What are Nonmetals?

Elements located on the right side of the periodic table that do not conduct electricity well.

What are Metalloids?

Elements that have properties of both metals and nonmetals, typically found along the diagonal line on the periodic table.

What are Alloys?

Mixtures of two or more metals.

What are Greek Prefixes used for?

Naming conventions used for molecular compounds to indicate the number of atoms.

what is the mass of a proton?

The mass of a proton is approximately 1.6×10−271.6×10−27 kg.

What is the conversion for gallons to liters?

1 gallon = 3.7854 liters.

What is an atom?

An atom is the smallest unit of an element that retains its properties.

What components make up an atom?

An atom consists of protons, neutrons, and electrons.

What is the charge and mass of a proton?

A proton has a charge of +1 and a mass of approximately 1.6×10−271.6×10−27 kg.

What is the charge and mass of an electron?

An electron has a charge of -1 and a mass of approximately 9×10−319×10−31 kg.

What is an isotope?

Isotopes are atoms of the same element that have different numbers of neutrons.

What does the atomic number represent

The atomic number represents the number of protons in an atom, which defines the element

What is the mass number?

The mass number is the total number of protons and neutrons in an atom.

How are atomic symbols written?

Atomic symbols are written in the format: [ Element SymbolMass Number^Atomic Number ] (e.g., 4He24He2 for helium).

What do the decimal numbers on the periodic table represent?

They represent the average atomic mass of an element, based on the relative abundances of its isotopes.

What happens to the charge of an atom if it gains or loses electrons?

If an atom gains electrons, it becomes negatively charged; if it loses electrons, it becomes positively charged

What is an intensive property?

A characteristic that doesn’t change regardless of the amount of substance, e.g., water's boiling point at 100°C.

What is unit analysis?

A method to ensure correct calculations by canceling out units.

What is a mixture?

A combination of two or more substances, e.g., methanol and propanol.

What is the law of definite proportions?

A chemical compound always has its elements in a fixed mass ratio, e.g., methane (CH4).

What is the law of multiple proportions?

When comparing compounds made of the same elements, different mass ratios can exist, e.g., carbon monoxide (CO) vs. carbon dioxide (CO2).

What is Dalton's atomic theory?

Proposes that all matter is made up of atoms, which are indivisible; chemical reactions involve rearrangement of atoms.

What did the cathode ray experiment show?

It demonstrated the existence of electrons as cathode rays could be deflected by magnetic fields.

What was determined by the Millikan oil drop experiment?

It established the small mass and charge of an electron using oil droplets and electric forces.

What is the plum pudding model?

An early model of atomic structure proposing electrons are within positively charged material.

What did the Rutherford gold foil experiment provide evidence for

It showed there is a dense nucleus in the atom, disproving the plum pudding model.

Why are Dalton's theories and models important?

They help in understanding key chemistry laws and how matter behaves in reactions.