explain the 5 particle theories of matter
1 All matter is made up of tiny particles 2 There are spaces between the particles 3 There are attractive forces between the particles. 4 The particles are always moving 5 Particles move faster at higher temperatures
if the temperature is higher how will it affect the reaction rate ?
Increased temp will increases the reaction rate.
How were the elements organised in the early periodic table?
Back then, the elements were organised by the Atomic Mass
What is atomic number?
The atomic number of an element is the number of protons in the nucleus of an atom.
What does reactivity mean?
how easily an atom loses or gain electron
Which of the two solutions increases reaction rate? A concentrated solution or dilute solution.
A concentrated solution
What happens during an endothermic reaction?
The reaction results in heat flow into the system causing the surroundings to feel cold
Who created the early periodic table?
Dimitri Mandeleev.
What is atomic mass?
The total number of protons and neutrons in an atom.
do metal want to lose or gain electron? what about non-metal
A metal can lose electron/ non metals gain electron
why does a chemical in powder form reacts faster then a large lump of the same mass?
Powder reacts faster because it has a greater surface area since the solid is broken down into smaller pieces, more particles are exposed leading to a higher frequency of successful collisions.
Burning fuels like methane or petrol is an example of exothermic/ endothermic reaction.
Why?
exothermic
Gives off heat
How are the elements now in the modern periodic table?
Now, the modern period table is organised by the Atomic Number.
What are the 3 subatomic particle? What are their charges? Where are they located?
Proton,Neutron and Electron. Proton is postive and neutron is neutral. They both located in nucleus of an element. Electron has negative charge and its located in atom shell.
What group of non-metals are the most reactive?
Most reactive is halogens/ group 17
How do catalysts speed up reaction rate?
It provides an alternative reaction pathway which lowers the activation energy, causing the reaction to occur faster.
Name three exothermic reactions
Combustion, respiration, hand warmers
what period is mercury in?
period 6
what group is iodine in?
group 17
Does reactivity increase or decrease going down a group for metals?
Reactivity increases
What is the effect of a catalyst on the rate of reaction?
It increases the reaction rate without getting consumed in the process.
What can form when particles collide with enough kinetic energy and the correct orientation?
New bonds.
What is the electron configuration in Hydrogen
1
What is the electron configurationof nitrogen?
2, 5
What does excited state mean?
An element has higher energy than its ground state