Key stage Chem

Which of the following pairs of elements are most likely to be metals?

When a metal is dropped into H₂O, a flame is observed, what may this metal be?

What are the products by thermal decomposition of zinc carbonate

Atomic number of B & D are 8 & 20. The formula of the compound formed between them is likely be

¹⁵X and ¹⁶X has R.A.M 15.2. What is the percentage abundance of the 2 isotopes ?

What is the type of this reaction? methane + oxygen → carbon dioxide + water

Element Y has an isotope as shown in the figure. Which statement of Y is incorrect

The flask becomes warm after Na is reacted with H₂O, what kind of reaction is this?

¹⁰³X & ¹⁰⁵X has relative abundance of 30% & 70% respectively. The relative atomic mass of X is?

Which of the statement is not correct about Group I elements?

Iodine has a mass number of 127 and atomic number of 53. How many protons does Iodine has?

Which period does an element with electronic configuration of 2,8,2 belongs to?

Which of the following pairs of ions has the same electronic configuration?

Which group in the periodic table is known as halogens?

What is the name of CH₄?