Science T1 (atoms) Flashcards
Physical changes can involve changes of state such as
Solids melting into liquids
Liquids freezing or solidifying into solids
Liquids vaporising into gases
Solids dissolving into solutions
Chemical changes can involve:
Colour change
Heat and light being produced
Bubbling
A precipitate forming
A new substance is formed
Are difficult to reverse
What is an Element
A substance that cannot be broken down into simpler substances by chemicals.
Matter definition
Matter is anything that has mass and volume (anything that takes up space). On earth found in solid, liquid, gas.
Atom definition
The atom is the basic unit of all matter, consisting of a dense central nucleus surrounded by a cloud of negatively charged electrons.
Elements definition
Elements are the basic building blocks of all matter and each element is made up of only one type of atom eg. Gold only contains gold atoms
Molecule definition
A molecule is a group 2 or more non-metal atoms bonded (or joined) together. Molecules can also be an element if they are only one type of atom e.g. O2 but they are a compound if they consist of more than one type of non-metal atom e.g. H2O
Compounds definition
A compound consists of atoms of two or more different elements bound together. Compounds that consist of non-metals bonded to metals are called ionic compounds e.g NaCl (sodium chloride or table salt). See above defintion for compounds that are also molecules
Atomic number
number of protons
The number of electrons an atom has is equal to the number of protons it has. Thus, atomic number also is
The number of electrons
The mass number
the number of nucleons (protons and neutrons)
To determine the number of neutrons
mass number - atomic number= neutrons
Which of the following is an example of a compound?
Water (H₂O)
Which group contains the alkali metals?
The alkali metals are found in Group 1 of the periodic table.
Lithium (Li)
Sodium (Na)
Potassium (K)
Rubidium (Rb)
Cesium (Cs)
Francium (Fr)
Which group consists of the noble gases?
The noble gases are found in Group 18 of the periodic table.
Helium (He)
Neon (Ne)
Argon (Ar)
Krypton (Kr)
Xenon (Xe)
Radon (Rn)
Oganesson (Og)
Which group contains the halogens?
The halogens are found in Group 17 of the periodic table.
Fluorine (F)
Chlorine (Cl)
Bromine (Br)
Iodine (I)
Astatine (At)
Tennessine (Ts)
What is the group number for the alkaline earth metals?
The alkaline earth metals are found in Group 2 of the periodic table:
Beryllium (Be)
Magnesium (Mg)
Calcium (Ca)
Strontium (Sr)
Barium (Ba)
Radium (Ra)
Number the group that includes the elements carbon and silicon.
The elements carbon (C) and silicon (Si) are found in Group 14 of the periodic table.
Which category includes elements with properties of both metals and nonmetals?
The category that includes elements with properties of both metals and nonmetals is called metalloids.
What are the group numbers that contain the transition metals?
The transition metals are found in Groups 3 to 12 of the periodic table. These elements are located in the central block and include:
Which group includes elements such as boron, aluminium, and gallium?
Group 13 of the periodic table. This group is often called the earth metals.
Name the group that includes elements like neon, helium, and argon.
The group that includes elements like neon (Ne), helium (He), and argon (Ar) is Group 18, also known as the noble gases.
List 6 elements that exist as diatomic gases
ix elements that exist as diatomic gases at room temperature are:
Hydrogen (H₂)
Nitrogen (N₂)
Oxygen (O₂)
Fluorine (F₂)
Chlorine (Cl₂)
Bromine (Br₂)
What statement can you make about the reactivity of the noble gases?
The noble gases are known for their low reactivity because they have full outer electron shells, making them chemically stable. As a result, they rarely form bonds with other elements.
What is the general name given to the rows on the periodic table?
periods.
How are elements represented on the periodic table?
by their atomic number and symbol
What is a molecule?
The smallest unit of a compound that retains its chemical properties.
Compounds can be separated into their constituent elements by physical means (True/False)
False: they can only be separated chemically
The chemical formula for water is H₃O
(True/False)
False
Elements can combine in different ratios to form different compounds. (True/False)
True
All substances are either elements or compounds. (True/False)
False: some substances are mixtures
The smallest particle of an element is called a
atom
A chemical bond is a force that holds
atoms together
A substance made up of two or more elements chemically combined in a fixed ratio is called a
compound
The chemical formula for table salt (sodium chloride) is
NaCl
the chemical formula for ammonia
NH₃
The chemical formula for Glucose
C₆H₁₂O₆.
Chemical formula for Water
Water – H₂O
Chemical formula for Methane
Methane – CH₄
Chemical formula for Sulfuric acid
H₂SO₄
Place these scientists in order according to their ideas about the atom, from earliest to latest.
Greek Philosophers
Dalton
thomson
rutherford
bohr
what was the nickname of J.J Thomson’s model of the atom
The plum pudding model
who held the idea that each material was made of a different atom
Ancient greeks
What turned out to be wrong with the plum pudding model
Atoms have a nucleus in the middle
When Rutherford fired alpha particles at a sheet of gold foil, he expected to see the particles go through the foil. What was the result of this experiment?
some particles bounced back
What was the difference between Rutherford’s model of the atom and Thomson’s model of the atom?
Rutherford’s model has a nucleus, and Thomson’s model didn’t
What was wrong with Rutherford’s model of the atom?
The electrons should be in shells
who discovered the neutron
James Chadwick
Why did Rutherford’s experiment show that most of the mass of the atom must be in a tiny nucleus?
Most alpha particles went through gaps between nuclei and a few alpha particles bounced back because they hit nuclei
Ionic =
Metal + Non-metal
Covalent=
non-metals
