Science Term 1 yr9 Flashcards
What is the formula for hydrogen gas?
H₂
What happened in the glowing splint test?
A glowing splint is introduced to oxygen gas and the flame reignites
What is the formula for ammonia?
NH₃
What are properties of the electrons?
Electrons orbit around the nucleus in the electron shells. Electrons have a relative charge of -1 and a mass of 0. They balance out the positive charged nucleus, meaning they have the same amount of protons as electrons.
What is the formula for gamma (y) radiation
0 y has no alternatives
0
In what order are the elements of the periodic table in?
They are arranged by atomic number. It mostly increases by atomic mass too, but there are some exceptions. The elements are also separated into metals, metalloids and non-metals.
What is the basic parts of a chemical equation?
Reactant + reactant → Product + product
What ionising ability does alpha decay have?
Very strong ionising ability
What is the formula for nitrogen gas?
N₂
What are valence electrons?
Valence electrons are the electrons on the outermost shell of the atom.
How can you figure out the number of Protons, Electrons and Neutrons in the nuclear symbol notation?
The number of protons and electrons is the number at the bottom. To figure out the number of neutrons you have to take the top number away from the bottom number.
What is the formula for water
H₂O
What is a daughter nuclide?
A daughter nuclide is the atom that is formed after beta or alpha decay
What is the formula for glucose?
C₆H₁₂O₆
What are rows and columns called in the periodic table
Rows in are called periods and columns are called groups. Elements in the same group have similar chemical properties.
What are the three subatomic particles in an atom?
Protons, neutrons and electrons
How can Atoms become more stable?
To become stable they must have a full outer shell. They can lose or gain electrons so that there is a full outer shell.
What is different about transition metal ions?
Transition metals can only be positive cations. When writing the formula for the transition metals you put the number of electrons lost as roman numerals in brackets. For example if copper lost two electrons it would be Copper (II) = Cu²+
What are the prefixes for naming covalent compounds?
My Mum Doesn’t Take The Pink Hat
M - Mono (1)
D - Di (2)
T - Tri (3)
T - Tetra (4)
P - Penta (5)
H - Hexa (6)
How are Covalent compounds written?
Prefix + atom 1 + Prefix + atom 2 + ide
What is the formula for silver?
Ag+
Define radioactive decay
The process of radioactive decay is the unstable nucleus trying to become more stable. It releases ionising radiation, which causes other surrounding atoms to become ions.
How fast is the alpha decay particle?
Slow moving because the a particle is “heavy”
Can you change subscripts in balancing chemical equations?
No, you cannot change the little number called subscripts in chemical equations balancing.
What is the formula for beta (b) decay?
0 or 0
-1 B -1 e
What is the formula for alpha (a) decay?
4 a or 4 He
2 2
What is gamma radiations penetrating ability?
It has a very high energy and high penetrating ability and is only stopped by lead
What can an aqueous be?
It is a system that involves water such as a substance dissolved in water, solution, acids or soluble salt.
What is the formula for chlorine gas?
Cl₂
What is a coefficient?
A coefficient is a large number in front of the compound that applies to the whole compound. For example 2HCl would mean there are 2 hydrogens and 2 chlorines.
What are properties of protons?
Have a relative charge of +1
Have a relative mass of 1 AMU
They determine what element the atom is. For example calcium has 20 protons. In a neutral atom, there are the same amount of electrons as protons. On the periodic table the number in the top right corner is the number of protons.
What is Mass number?
Mass number is the number of protons and neutrons added together.
How are ionic compounds formed?
When an atom needs to get rid of an electron it will find another atom that needs an electron and it will give that electron to it. This will result in the two atoms have opposite charges and they will attract together. For example Li+ and F- would create LiF.
What are properties of the neutrons?
They are neutrally charged and have a relative mass of 1. They help stabilise the nucleus. The number of neutrons can vary between atoms of the same element. E.g. Calcium always has 20 protons but one atom might have 19 neutrons and another 20. The amount of neutrons in an atom on the periodic table is usually calculated by taking the atomic mass by the atomic number.
How is the nuclear symbol notation set out?
Mass number on top (number of protons and neutrons) Then the atomic number underneath and the element symbol to the right of it.
What are the two parts Atoms are made up of?
- Positively charged nucleus in the centre
- Electron shells that surround the nucleus
How are covalent compounds formed?
When two atoms both need to gain and electron, they will combine and share the electron. For example if two Fluorine both need an electron they will combine to form F + F = F2
What is alpha decay’s penetrating ability?
It has a low penetrating ability and is stopped by paper, air and skin.
In what order are ionic compounds named?
Cation + Anion or Metal + non-metal. The compound should end in a different ending. eg. Sodium Fluoride.
What are the four states of matter and their symbol?
Solid (s), gas (g), liquid (l) and aqueous (aq)
What are the group names of the periodic table?
AATLAHN
Group 1: Alkali metals
Group 2: Alkaline Earth metals
Group 3-12: Transition metals
Group 8: Lanthanide series
Group 9: Actinide series
Group 17: Halogens
Group 18: Nobel gases
How does an element become negatively charged?
An element becomes negatively charged when it gains electrons. When it is negatively charged the elements name changes to end with iod. For example Fluorine would go to Fluoride.
What is Beta decays penetrating ability?
Moderate penetrating ability but is stopped by aluminium
What is the atomic number?
The Atomic number is the number of protons (and electrons) in the element.
Define a covalent compound?
Involve the sharing of electrons between non-metals to get a full outer shell
What are the properties of a solid element?
If an element is a metal by itself, a precipitate or an insoluble salt then it is a solid.
What is the formula for methane?
CH₄
How does gamma radiation work?
Sometimes after alpha or beta decay, the daughter nuclide (the one that’s formed) can have too much energy. The daughter nucleus can then release that excess energy in the form of gamma radiation
Define an Isotope
An isotope is an element that has a different number of neutrons than protons in the nucleus. Some combinations of this are stable and some are unstable. Isotopes are very rare in some elements.
What are cations?
Cations are elements that have a positive charge (have lost electrons).
Define an Ionic compound?
Involves the movement of electrons from a metal cation to a non-metal anion.
What do the brackets in equations mean?
A number outside a bracket means all the elements inside the bracket are multiplied by that number. For example Mg (OH)₂ means there is one magnesium, two oxygen and two hydrogen.
What happened in the pop test?
A flame is introduced to hydrogen gas and a pop or squeak noise is made. It is a simple chemical experiment used to identify the presence of hydrogen gas by observing a small, explosive reaction when a lit splint is brought near the mouth of a test tube containing the gas.
What ionising ability does Beta decay have?
Medium ionising power
What is the formula for Lead?
Pb²+
What is the formula for Ziac?
Zn²+
How do you know if an element or compound is a gas?
If it is a known gas such as O2, H2, CO2
How do Beta particles work?
Beta particles are high energy electrons that are emitted as the nucleus charge. A neutron changes into a proton and a B particle is emitted. This is to make the nucleus more stable. The new atom will have one more proton and one less neutron meaning the mass number will stay the same.
What are anions?
Anions are elements that have a negative charge (have gained electrons).
How fast is the Beta decay particle?
Moderate particle speed (0.3 - 0.8 times the speed of light)
How does alpha decay work?
When an atom has too many nuetrons and is unstable it decays and releases an a particle from its nucleus. As a result of losing 2 protons and 2 neutrons, it changes to a new atom type.
What is the law of conservation of mass?
The law of conservation of mass states that the number and type of atoms that we start with will be the same after the reaction. The only that changes is how they’re arranged.
How fast is Gamma radiation?
Moves at the speed of light
What makes an isotope unstable?
If it has a big difference in neutrons and protons. If there are too many or too little neutrons it becomes unstable. Unstable isotopes are radioactive.
what are the properties of a liquid element?
The only liquid is water. Anything else is not a liquid
What happens in the limewater test?
Carbon dioxide is bubbled through limewater. The limewater goes cloudy
What ionising ability does gamma radiation have?
Low ionising ability
Explain the purpose of half life
Half life is used to see how long it will take a radioactive particle to decay. Radioactive decay can happen at anytime and is spontaneous. However, each radiactive isotope has a specific half life. For example Hydrogen 3 might have 20 year half life, whilst Hydrogen 2 might only have a 3 minute one
How do you write the formulas for ionic compounds?
The swap and drop method. Example: Li+ and O²-. The 1+ and 2- would swap places to from Li₂O
What is the formula for oxygen gas?
O₂
How does an element become positively charged?
For an element to become positively charged it must lose a negatively charged electron. When an element is positively charged it is written as the element symbol and a plus. For example, Na+
What is the pattern for filling up the electron configuration
2,8,8,2
