Science term 1 notes

What is a periodic table

The periodic table is an arrangement of elements in order of increasing proton number

What is the vertical columns of elements in the periodic table called?

Groups

What is the horizontal rows of element in the periodic table called?

Periods

What is group 1 of periodic table

Alkali Metal

What is group 2 of periodic table

Alkaline Earth metals

What is group 17 of periodic table

Halogens

What is group 18 of periodic table

Noble Gases

What is group 3 to 12 of periodic table

Transition metal

Porperties of transition metals (high ___ and high _____)

High melting points and high densities

Elements in the same group have similar c___ properties and undergo the same type of c___ r____

Chemical properties, chemical reaction

Do metals or non-metals lose valence electron to form ions?

Left side (metals) lose valence electron while the right side (non-metal) gain valence electron

Transition metals can form ions of different c___

charges

What are the elements with both metal and non-metal properties called?

metalloids

What is the zigzag line that divides non-metal and metals? (metalloids is found along this line too)

here

For metals, does reactivity increase or decrease as you go down a group?

Increase

For non-metals, does reactivity increase or decrease as you go down a group?

Decrease

When atoms of elements react, they try to obtain a s___ e____ c____

stable electronic configuration

Are noble gases reactive?

No

Which two kinds of stable electronic configuration exist? (structure)

duplet structure, octet structure

Which type of bonding is usually seen in compounds of non-metal?

Convalent bonds

Which type of bonding is seen in a hyrdrogen molecule (single, double or triple) and what structure does it have?

Single convalent bond with duplet structure

What is valency?

The number of electrons an atom used to form bonds is called its valency

How to draw structural formula of methane (CH4)

Each line represents one pair of electrons being shared

Do simple molecules (such as H2 and F2) have strong or weak covalent bonding within each molecule?

Strong

Between molecules (covalent bonding), is the intermolecular forces strong or weak? (and does this result in these substances having low or high melting and boiling points.

Weak, low boiling point and low melting point

What is the type of compounds usually formed between metals and non-metals

Ionic compounds

What does ionic bonding refer to> (e____ f___ of a___)

electronic forces of attraction between ions of opposite charge

What structure is formed when very large number of ions (from ionic bonding) come together?

Lattice structure

Is ionic bonding strong or weak? (low or high melting and boiling points)

Strong, high melting and boiling points

Draw the dot-and-cross diagram for magnesium chloride

Ionic compounds can also be monatomic and ____atomic

polyatomic

ammonium symbol

NH4+

Silver

Ag+

Zinc symbol

Zn (2+)

copper(II) symbol

Cu (2+)

Aluminium

Al (3+)

hydroxide symbol

NH-

nitrate symbol

NO3-

hydrogencarbonate (bicarbonate) symbol

HCO3-

Hydroxide symbol

H-

Hydrogen symbol

H+

oxide symbol

O (2-)

Sulfide symbol

S (2-)

Sulfate symbol

SO4 (2-)

carbonate symbol

CO3 (2-)

peroxide symbol

O2 (2-)

phosphate symbol

PO4 (3-)

nitride symbol

N (3-)

What’s the charge of an ionic compound and why?

Ionic compound have no net charge as the positive charge must equal the negative charge

What is the formula of ionic compound between Pb (4+) and O (2-)

PhO2

What does the chemical formula of an ionic compound also represent? (it is the lowest number of cations and anions in the ionic lattice)

formula unit

Difference between mixture and compound

Mixture is impure and not chemically bonded together while compounds are chemically bonded together and pure

What type of bond does a molecule have?

Covalent bond

What is atoms made up of?

Electrons, neutrons, protons

What is nuclear decay?

Nuclear decay is a random process by which an unstable atomic nucleus loses it energy by emission of electromagnetic radiation or particle(s).

What is alpha decay?

it is when the nucleus emits an alpha particle, identical to a helium-2 nucleus

What is beta decay?

it is when the nucleus emits a beta particle, which is a fast-moving electron

What is gamma radiation and when is it produced?

When the nucleus undergo alpha decay or beta decay, gamma radiation is emitted

What the two important conservation rule in all nuclear decay processes and reactions?

Conservation of mass and conservation of charge

What is nuclear fission?

Nuclear fission is a process in which the nucleus of an atom splits (usually into two parts) and release a large amount of energy

Nuclear Fusion

Nuclear fusion is when two light atomic nuclei combine to form one heavier atomic nucleus (of a different element) and release a large amount of energy

What is a chemical equation used to describe?

a chemical change

What is the symbols and formulas on the left side of a chemical equation called?

Reactants

What is the symbols and formulas on the right side of a chemical equation called?

Products

Practise equation writing

Go on internet and search for some practices

What is an acid?

An acid is a molecule which when dissolved in water, dissociates to form hydrogen ions.

What does the dissociation of an acid molecule refer to?

It refers to the breakage of the covalent bond linking a hydrogen atom to another atom.

Can acid solutions conduct electricity?

Yes

Name an unqiue thing about acid molecules

Acids have simpler molecular structure but still dissociates to give mobile ions to conduct electricity.

What is the chemical formula of hydrochloric acid? (and is it strong or weak?)

HCl, strong

What is the chemical formula of nitric acid? (and is it strong or weak?)

HNO3, strong

What is the chemical formula of sulfuric acids? (and is it strong or weak?)

H2SO4, strong

What is the chemical formula for ethanoic acid? (and is it strong or weak?)

CH3CO2H, weak

What is a strong acid?

A strong acid is one that dissociate completely in water to produce hydrogen ions.

What is a weak acid?

A weak acid is one that dissociates partially in water to form hydrogen ions

How do you measure the strength of an acid?

Its the extent of dissociation of the acid in water to form hydrogen ions

What is the importance of water for acids?

Acid molecules are not acidic when pure or dissolved in other solvent as no dissociation occurs to form hydrogen ions. It is only acidic when in water

What do acids taste like?

Sour

What do acids react with?

metals, carbonates and bases

What is produced when acids react with metals?

salt and hydrogen gas

What is observed when acids react with metal? (2 things)

Effervescence of colourless, odourless gas, which extinguished a lighted wooden splint with a ‘pop’ sound

Heat is liberated

Solid dissolves to form a colourless solution (if it is the liming reagent) i dont know if this one is even tested or what

What is the full metal reactivity series? (for acids)

(please send cats monkeys and zebras in lovely happy cages made of silver & gold)

K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au

What is the product of acids reacting with carbonate

Salt, water, carbon dioxide gas

Observation of acid reacting with carbonate

Effervescence of colourless, odourless gas which produces a white precipitate when bubbled into limewater (aqueous calcium hydroxide)

White solid dissolves to form a colourless solution

What is the product of acids reacting with bases

salt and water (neutralisation)

What is observed when acids react with bases

White solid dissolves to form a colourless solution

Heat is liberated

What is an use of hydrochloric acid

food processing

what is an use of nitric acid

manufacture of fertilisers

what is an use for sulfric acid

Batteries for vehicles

what is an use for citric acid

lemons, food industry

what is an use for carbonic acid

manufacture of carbonated drinks

what is an use for ethanoic acid

manufacture of aspirin

What is low pH numbers? (and what pH is it)

less than pH 7, acids

What is high pH numbers? (and what pH is it)

more than pH 7, alkaline

If a substance has the pH of 7, is it acidic or alkaline?

It is pH-neutral, neither acidic or alkaline

What does hydrogen ions and hydroxide ions tend to form

water molecules

What is the colour of litmus paper in acids and alkalis?

red in acids and blue in alkalis

What is the colour of litmus solution in acids and alkalis?

red in acids and blue in alkalis, purple at neutral pH

what is the colour of methyl orange at different pH levels?

red below pH 3.1, yellow above pH 4.4 and varying degrees of orange between 3.1 and 4.4

what is the colour of phenolphthalein at different pH levels?

colourless below pH 8.1, pink above pH 10.0, varying degree of faint pink between 8.1 and 10.0