1 What A is all matter made of?
2 Which scientist first came up with a model of what atoms are like?
3 How did Dalton describe atoms?
tiny indestructible spheres
4 How did he use his model to explain elements?
all the atoms in an element were identical (and different from other elements)
5 What is the difference between an atom and a molecule?
molecules contain two or more atoms chemically joined together in a group
6 How did Dalton explain what happened when compounds were formed?
atoms of different elements joined together to form the compound
7 What tiny particles flow in an electric current?
8 What charge do electrons particles have?
9 What particles are found in an atom?
protons, neutrons and electrons
10 What is the nucleus of an atom?
tiny central part of an atom made up of protons and neutrons
11 How have Daltons ideas about atoms changed?
atoms are not indestructible but are made up of smaller particles (protons, neutrons and electrons)
12 What are the names of the three main subatomic particles?
protons, neutrons, electrons
13 What is the nucleus of a helium atom made up of?
protons and neutrons
14 How are electrons arranged in an atom?
circling/orbiting the nucleus in regions called shells
15 How do protons and electrons compare in terms of relative charge?
protons have a positive (+1) charge and electrons have a negative (-1) charge
16 Why are most atoms neutral?
they have the same number of protons and electrons and so equal positive and negative charges
17 What is the fundamental difference between atoms of different elements?
they contain different numbers of protons
18 How does the size of a nucleus compare to the size of the atom?
the nucleus is tiny compared to the size of the atom
19 How many protons are there in an atom with an atomic number of 26?
20 How many neutrons are there in an atom with an atomic number of 26 and a mass number of 56?
30 (56 - 26) The number of neutrons is the mass number minus the atomic number
21 Which subatomic particles are found in the nuclei of most atoms?
protons and neutrons
22 What does the atomic number of an atom tell you about its structure?
the number of protons in an atom
23 What does the mass number of an atom equal?
the number of protons plus the number of neutrons
24 What will be the same about atoms of the same element?
they will have the same atomic number and same number of protons
25 Where is most of the mass of an atom found?
in the nucleus
26 Which subatomic particles in an atom have negligible mass?
27 How many electrons are in an atom with a mass number of 56 and an atomic number of 26?
26 (It will have 26 protons and therefore 26 electrons if it is neutral)
28 How many protons, neutrons and electrons are in an atom that has an atomic number of 13 and a mass number of 27?
13 protons, 14 neutrons, 13 electrons
29 What are isotopes?
atoms with the same atomic number but different mass numbers (this is due to them having a different number of neutrons)
30 What type of atom is used as the standard for comparing masses and working out relative atomic masses of elements?