The diagram shows the electron structures of some elements.
Which two elements have similar chemical properties?
☐ | A | A and B | |
☐ | B | A and C | |
☐ | C | B and C | |
☐ | D | B and D |
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The diagram shows the electron structures of some elements.
Which two elements have similar chemical properties?
☐ | A | A and B | |
☐ | B | A and C | |
☐ | C | B and C | |
☐ | D | B and D |
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In Figure 8, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table.
These letters are not the symbols of the atoms of these elements.
Figure 8
Using the letters A, E, G, J, X and Z
Element E has an atomic number of 5.
In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.
(2)
Element X has an atomic number of 18.
State the electronic configuration of an atom of element X.
In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.
Calculate the empirical formula of this compound.
(relative atomic masses: A = 7, G = 16)
You must show your working.
An oxygen atom has six electrons in its outer shell.
A hydrogen atom has one electron in its outer shell.
Complete the dot and cross diagram of a molecule of water, H2O.
Show outer shell electrons only.
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An element has the configuration 2.8.3.
Which group and period is this element in?
Group | Period | |||
☐ | A | 2 | 8 | |
☐ | B | 3 | 3 | |
☐ | C | 2 | 3 | |
☐ | D | 3 | 2 |
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Mendeleev arranged the elements in order of atomic mass.
He then reversed the order of some pairs of elements.
Why did he do this?
☐ | A | To put them in order of atomic number | |
☐ | B | To group elements according to their properties | |
☐ | C | To leave gaps for undiscovered elements | |
☐ | D | To ensure elements were in the same period |
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Figure 1 below shows the periodic table Mendeleev produced in 1869.
His periodic table was more widely accepted than previous versions
Figure 1
The atomic weight of iodine (I) is 127 and that of tellurium (Te) is 128.
Why did Mendeleev reverse the order of these two elements?
Why did Mendeleev leave gaps for undiscovered elements?
Name the particle that allowed the elements to be arranged in order of their atomic number in the modern Periodic Table.
Mendeleev's periodic table shows lithium, sodium and potassium all in the same column.
These elements are in the same column, Group 1, of the modern periodic table.
Explain the reactivity of these elements going down Group 1.
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