Yr 9 science Final Exam Flashcards
An element is?
A element is atoms that all have the same number of protons in their nucleus
A compound is
A compound is a combination of different elements into a single unit
Give example -water h20 carbon dioxide CO2
What is an Atom?
The smallest single unit of an element
What is a proton
It’s a tiny particle that has a positive charged particle inside the nucleus
Define electron
It’s a negative particle that revolves around the outside of the atoms nucleus
A neutron is?
It’s a particle of matter that has no charge
A nucleus of an atom contains what?
Protons and neutrons
The charge of the nucleus is?
Positive
Because ?
The nucleus of an atom contains protons ( positive charge) and neutrons( no charge ) so the overall charge is positive .
Most of the weight of an atom is where?
In the nucleus of the atom
Metals are located where on the periodic table
Left side
Non metals are located where on the periodic table
Right side
Metalloids are located where on the periodic table ?
In between metals and non metals .
Define Matter?
Matter is a substance it’s anything that takes up space .
eg:everything around you - people, food, cars etc
All the atoms and molecules around you
The size of an atom is determined by what?
The orbit of electrons around the nucleus
The atomic number of an atom explains how many protons are in a nucleus true or false
True
The atomic mass of an atom is the total number of ?
Protons and neutrons in the nucleus of an atom
The early Greek model of the atom was that matter was made of what
Small indivisible units that could not be seen and the smallest piece of matter
Ernest Rutherford discovered that the nucleus of atoms was big compared to the size of atom
T or F
False
They were very small compared to the size of atom
What is a alpha particle
It is a helium nucleus
What does an alpha particle contain
Two protons and two neutrons
Why?
Because it has no electrons it has a charge of 2+
What is a beta particle
It is a negatively charged particle
What is it commonly referred to ? A fast moving electron
The periodic table lists atoms in order of increasing what?
Atomic number
Where on the periodic table is The alkali group?
Group 1
Where are the alkaline earths located in the periodic table
Located in group two
The noble gases are group 8 in the periodic table. The outer electron shell of noble gases always contains
A gases
B a full shell of electrons
C a particle
D single unit
Do the number of electrons and protons in an atom stay the same
True
The negative charge cancels out the positive charge
When the number of electrons and protons are not the same it is no longer an atom .. What is it?
An ion
Gases are located where on the periodic table
The right side .
The gases in group 8 are known as what? The noble gases
How many electrons do the elements in group 1 have?
One electron in the outermost shell
Do the elements in group four of the periodic table have four electrons in the outermost shell t or f
True
When magnesium is burned in air what new chemical is formed
Magnesium oxide
When acid is added to magnesium what gas is produced
Hydrogen
What is the test for this gas called ? The pop test , because when hydrogen is captured in a test tube it causes a lit match to pop.
When acid is added to calcium carbonate what gas is produced
Carbon dioxide
When you add ice to a chemical reaction what happens
It makes the reaction go slower
List five ways to increase the speed of a chemical reaction
Heating , pressure, surface area, type of reactants, concentration of reactants
The cloud model of an atom is best explained as what?
A small nucleus around which the electrons circulate but there position is unknown
Tell ME the difference between a molecule and a compound
A molecule is formed when 2 or more atoms join together chemically
A compound is a molecule that has 2 different elements
So all compounds are molecules but not all molecules are compounds
A neutralisation reaction occurs when what are combined
Equal amount of acid and base
Burning a chemical in the presence of oxygen is called a what reaction
A combustion reaction
Isotopes of an element are different because of what
Because they have different numbers of protons
Why is ionising radiation dangerous
Because it can cause damage to human cells and can result in cancer
Radioactivity is the emission of two particles what are the particles
Beta particles and alpha particles
Or
Gamma waves from an atom
The half life of a radioactive element is the time it takes for the radioactivity of the atoms to
A split
B half
C decay
D dance
How many number of atoms in a molecule of glucose
24
6 carbon, 12 hydrogen, 6 oxygen
Neutral solutions have a ph equal to
7
Acidic solutions have a ph level of less than
A 4
B7 answer
C 8
D 2
What solution has a ph level of more than 7
A basic solution
A inventor called Mendeleev invented what
The periodic table
List 3 common acids
Sulphuric acid, nitric acid, hydrochloric acid
List a common base
Sodium hydroxide also known as caustic soda
A Geiger counter is used to detect what
Radiation
Carbon dating can only be used on what type of materials
On materials that were once living
