This question is about potassium and zinc - Edexcel - GCSE Chemistry - Question 5 - 2021 - Paper 1
Question 5
This question is about potassium and zinc.
(a) Which of the following temperatures is most likely to be the melting point of potassium?
A -63°C
B 6.3°C
C 63°C
D ... show full transcript
Worked Solution & Example Answer:This question is about potassium and zinc - Edexcel - GCSE Chemistry - Question 5 - 2021 - Paper 1
Step 1
Which of the following temperatures is most likely to be the melting point of potassium?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The most likely melting point of potassium is C 63°C. Alkali metals, including potassium, generally have low melting points, and at 63°C, potassium would be solid, while option D (630°C) is too high.
Step 2
Explain how the electronic configuration of an atom of potassium is related to its position in the periodic table.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Potassium has one electron in its outer shell, which places it in Group 1 of the periodic table. The position in the periodic table indicates that it has a single outer electron, and as it belongs to Period 4, it has four electron shells.
Step 3
Describe the test to show that a gas is oxygen.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To test for oxygen, you can use a glowing splint. When a glowing splint is introduced to the gas, it will reignite if oxygen is present.
Step 4
Write the electronic configurations for the ions in potassium oxide, K₂O.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
