Chemistry EOY Flashcards
(23 cards)
What is ionic bonding?
The electrostatic attraction between positively and negatively charged ions formed by electron transfer between metals and non-metals.
Which elements typically form positive ions?
Metals
Which elements typically form negative ions?
Non-metals.
What is covalent bonding?
The sharing of pairs of electrons between non-metal atoms.
Why do atoms share electrons in covalent bonding?
To achieve a stable outer shell (like noble gases).
What are the key properties of alkali metals?
Soft, low melting points, very reactive with water, form +1 ions.
Why do alkali metals become more reactive as you go down the group?
The outer electron is further from the nucleus and more easily lost.
What are the key properties of halogens?
Coloured, diatomic molecules, form -1 ions, reactivity decreases down the group.
What is a displacement reaction in halogens?
A more reactive halogen displaces a less reactive one from its salt.
What is the approximate composition of air?
~78% nitrogen, ~21% oxygen, ~1% argon, ~0.04% carbon dioxide
What is the reactivity series?
A list of metals ranked by how easily they react (e.g. K, Na, Ca, Mg, Al, Zn, Fe, Cu).
How can you determine a metal’s place in the series?
By its reaction with water, acids, and other metal salts.
What is an acid?
A substance that releases H⁺ ions in water.
What is an alkali?
A soluble base that releases OH⁻ ions in water.
What is the pH of acids, alkalis and neutral solutions?
Acids: <7; Neutral: 7; Alkalis: >7.
What is neutralisation?
Reaction of an acid with a base to form salt and water.
Give an example of a neutralisation reaction.
HCl + NaOH → NaCl + H₂O.
How do you prepare a soluble salt (like copper sulfate) from an insoluble base?
Add base to acid until neutral, filter, then crystallise.
How do you test for hydrogen gas?
Pop’ test – a lit splint makes a squeaky pop.
How do you test for carbon dioxide?
Turns limewater milky (cloudy).
How do you test for chlorine gas?
Bleaches damp litmus paper.
What is an isotope?
Atoms of the same element with the same number of protons but different numbers of neutrons.
