Topic 1 Structure of atom and Periodic Table Flashcards
1 What A is all matter made of?
atoms
2 Which scientist first came up with a model of what atoms are like?
Dalton
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?
electrons
8 What charge do electrons particles have?
negative
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?
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?
electrons
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?
carbon-12
31 Which element has the chemical symbol O?
oxygen
32 What is the chemical symbol for carbon?
C
33 Which element has the chemical symbol Mg?
magnesium
34 What is the chemical symbol for sodium?
Na
35 Which type of substance is found in the periodic table – elements, compounds or mixtures?
elements (its called the Periodic Table of Elements !!)
36 What is a vertical column in the periodic table called?
group
37 What is a horizontal row in the periodic table called?
period
38 What is the number on the periodic table used to compare the masses of atoms of different elements (it takes into account the different isotopes and amounts) ?
relative atomic masses
39 Name the Russian chemist who developed a periodic table in 1869.
Mendeleev/Dmitri Mendeleev
40 In general, what is a scientific prediction?
what you think will happen and why you think this
41 In what year did Mendeleev first develop a periodic table?
1869
42 About how many elements are there in the modern periodic table?
about 100 or 118 exactly
43 Where are the non-metals placed in the modern periodic table?
right-hand side/top right
44 Which number tells you how many protons there are in a nucleus?
atomic number/proton number
45 Sodium atoms have 11 electrons. How many protons do they have?
11 (Because it is a neutral atom and the number of protons = the number of electrons)
46 Where are electrons found in an atom?
around the nucleus/in shells/in energy levels
47 What is a period in the modern periodic table?
a row of elements (a row is the one that goes along a column is the one that goes down!!)
48 What is a vertical column in the modern periodic table called?
group
49 Which element’s position was swapped with tellurium by Mendeleev?
iodine (He swapped them to ensure that they were in the correct group, with elements of similar properties)
50 What property did Mendeleev use to order the elements?
atomic weight/relative atomic mass (Medeleev used mass the modern periodic table uses atomic number!!)
51 What do modern atomic numbers tell you about an atom?
the number of protons in the nucleus
52 Where are elements with similar properties placed in the periodic table?
in the same groups/columns
53 Where do the atomic numbers increase by 1 each time in the periodic table?
in a period (as you move along a period the atomic number increases by 1)
54 Where are the shells found in an atom?
around the nucleus
55 Why might a modern periodic table have gaps in it?
for as yet undiscovered/synthesised elements (they are all at the end of the Modern Periodic Table)
56 Name a group 0 element.
helium/neon/argon/krypton/xenon/radon/ununoctium
57 Is an atom a zero-, one-, two,- or three- dimensional object?
three-dimensional
58 Name the physicist who discovered a relationship between atomic number and X-rays emitted by atoms bombarded by electrons.
Moseley/Henry Moseley
59 The atomic number of chlorine is 17. How many electrons do its atoms have?
17 (It has 17 protons and is neutral and therefore has 17 electrons)
- What are the two main isotopes of chlorine?
Chlorine-35 and Chlorine-37