Y10 Science Atomic structure Flashcards
What is a Chemical change?
When a new substance forms during a chemical reaction due to bond breaking and forming.
What is a physical change?
A change of state, between solid, liquid, or gas or a change in shape and no new substance is formed.
Chemical change indicators
Buring/fire
Change in colour
Change in odour
Explosions
Bubbles or fizzing
Sound
What is an ion?
An ion is an atom that has gained a positive or negative charge by taking or losing electrons.
How are elements arrange on the periodic table?
The chemical elements are arranged in order of increasing atomic number. The rows (across the table) are called periods and the columns (down the table) are called groups. Metals are found on the left side of the periodic table and non-metals are found on the right side of the periodic table.
What do group numbers tell us?
The number of electrons in the outer valance shell. They have similar chemical reactions.
What do period numbers tell us?
How many electron shells it has.
Why are atoms are neutral overall?
Atoms have the same number of protons (+1 charge) and electrons (-1 charge). Therefore these charges cancel each other out and the atom has no overall charge making it neutral. Neutrons are neutral, so these do not affect the charge.
Why does magnesium form an ion with a 2+ charge?
A magnesium atom is in group 2 because it has 2 valence electrons. To achieve a full shell and become stable, it loses 2 electrons and becomes the magnesium ion Mg2+. Protons are positive, and electrons are negative. As there are 12 positive protons and 10 negative electrons, there are 2 more positives than negatives, so the charge is +2 overall.
Why does oxygen form an ion with a 2- charge?
An oxygen atom is in group 16 because it has 6 valence electrons, to achieve a full shell and become stable it gains 2 electrons and becomes the oxide ion O2-. Protons are positive, and electrons are negative. There are 8 protons and 10 electrons, as there are 2 more negatives than positives, so the charge is -2 overall.
Explain ionic bonding including the transfer of electrons.
Ionic bonding occurs between two oppositely charged ions that are attracted to one another due to electrostatic forces. To form the ions, an (metal) atom will lose valence(s) electrons to form a full valence shell and become stable. The electron(s) lost will be gained by another (non-metal) atom to also fill its valence shell and become stable. This forms the anion and cation which form the ionic bond and results in an ionic compound.
What is metallic bonding?
Metallic bonding occurs when metal atoms ‘lose’ their outermost electrons, which form a “sea of electrons” that moves freely throughout the structure. The atoms, now positively charged cations, are arranged in a lattice and are held together by the electrostatic attraction between the cations and the negatively
What are the diatomic molecules?
O2, Cl2, H2, I2, Ba2, F2, N2
Describe covalent bonding
Non-metal elements are located on the right hand side of the periodic table and they will form covalent bonds where they share a pair/s of electrons with each other to fill their valence shells.
Compare covalent, ionic and metallic bonding.
Covalent bonds are formed when a substance contains non-metal elements (located on the right hand side of the periodic table). The ATOMS will form covalent bonds where they share a pair/s of electrons with each other to fill their valence shells. Whereas, ionic bonding occurs between metal and non-metal elements. Ionic bonding occurs between two oppositely charged ions that are attracted to one another due to electrostatic forces. To form the ions, a (metal) atom will lose valence(s) electrons to form a full valence shell and become stable. The electron(s) lost will be gained by another (non-metal) atom to also fill its valence shell and become stable. This forms the anion and cation which are electrostatically attracted to each other - this is the ionic bond - and results in an ionic compound. Furthermore, metallic bonding occurs when a substance contains only metal elements. Metallic bonding occurs when metal atoms ‘lose’ their outermost electrons, which form a “sea of electrons” that moves freely throughout the structure. The atoms, now positively charged cations, are arranged in a lattice and are held together by the electrostatic attraction between the cations and the negatively charged electrons. This strong attraction is called a metallic bond.
