Chemistry - Basics of Chemistry Test #2

definite shape and definite volume

solid

indefinite shape (takes shape of its container) and definite volume

liquid

indefinite shape and indefinite volume( takes shape of its container/ fills container)

gas

matter made of any one type of atom ( pure gold, sulfur, oxygen)

element

matter made up of more than 1 element in a fixed ratio

compound

a mixture that has a consistent composition - solution always the same

homogenous

milk, salt water ,

expls of homogeneous

a mixture with distinct phases - different

heterogenous

oil & vinegar, orange juice, cornstarch & water

expls of heterogenous

Matter cannot be created or destroyed in a chemical reaction; it can only change forms. The total mass of reactants equals the total mass of products.

law of conservation matter

A chemical compound always contains the same elements in the same fixed ratio by mass, no matter the source or amount.

law of definite proportions

Dalton used these laws to propose that matter is made of indivisible atoms:

The Law of Conservation of Matter suggested atoms are not created or destroyed in reactions.

The Law of Definite Proportions suggested compounds are made of atoms combined in fixed ratios.

How laws contributed to daltons atom theory

All matter is made of tiny atoms.

Atoms of the same element are identical.

Atoms cannot be created or destroyed.

Atoms combine in fixed ratios to form compounds.

Chemical reactions rearrange atoms but do not change them

daltons atomic theory

Modern Atomic Theory shows that atoms are divisible into subatomic particles: protons, neutrons, and electrons

How Modern Atomic Theory changed the idea that atoms are indivisible

Atoms of the same element can have different numbers of neutrons, forming isotopes, so they are not always identical in mass

How Modern Atomic Theory changed the idea that all atoms of the same element are identical

Matter is made of atoms.

Atoms combine in fixed ratios to form compounds.

Chemical reactions rearrange atoms rather than creating or destroying them.

parts of daltons theory that are still correct

3 element articles of an atom

protons,neutrons,electrons

Where is the proton located in an atom

nucleus

Where is the neutron located in an atom

nucleus

What is the charge and relative mass of a neutron

charge: 0 (neutral) mass: ~1 amu

What is the charge and relative mass of a proton

charge: +1 Mass: ~1 atomic mass unit (amu)

Where is the electron located in an atom

electron cloud

What is the charge and relative mass of an electron

charge: -1 ,mass: ~1/1836 of an amu

What is the atomic number, and what does it tell you?

The atomic number is the number of protons in an atom. In a neutral atom, it also equals the number of electrons

How do you find the number of neutrons in an atom

Neutrons = Mass number – Atomic number

In hyphen notation, how is an isotope written

[Element name]-[Mass number], e.g., Carbon-14.

In nuclide notation, how is an isotope written

mass number/ atomic number number element symbol

How do you determine the number of electrons in an ion

For a positive ion (cation), electrons = protons – charge.

For a negative ion (anion), electrons = protons + charge

atoms of the same element that have the same number of protons but different numbers of neutrons, giving them different mass numbers.

isotope

How are isotopes represented in nuclide notation

weighted average of the masses of all naturally occurring isotopes, based on their relative abundances

average atomic mass of an element

how do you calculate average atomic mass

a unit that represents 6.022 × 10²³ particles (atoms, molecules, or ions) of a substance. This number is called Avogadro’s number

mole

What is the relationship between moles and number of particles (atoms/molecules)

number of particles=moles×6.022×10^23 (avogadro’s number)

What is the relationship between moles and mass

How do you find moles if you know the number of atoms or molecules?

How do you find moles if you know the mass of a substance?

Color

Density

Melting point / Boiling point

Solubility

Hardness

physical properties used to determine substances

Reactivity with acids or bases

Flammability

Oxidation states

Ability to rust or corrode

chemical properties used to identify substances

characteristics that can be observed  or measured without changing a substance identity

physical change

characteristics that can only be observed by changing a substance idenity

chemical change

properties that require measurement

quantitative

properties that can be observed without measurement

qualitative

shape, color, texture

qualitative

mass, volume, density

quantitative

flammability, rusting

exps of chemical change

mass, temp, volume

exps of physical change

smallest unit of matter that has its own unique properties

atom

a substance made of 2 or more atoms

molecules

types of molecules ex; water, sugar, salt

compounds

atom, molecule, compound

basic units of matter