Which of the following is true about an atom of iron and an atom of copper? 1 they have different masses. 2 both have the same properties. 3 they have an equal number of protons. 4 both have different types of sub-atomic particles.

Option (1) is the correct answer.

Explanation:

Both iron and copper atoms are transition elements. Atomic number of iron is 26 and atomic number of copper is 29.

As it is known that when atoms are neutral then number of protons and number of electrons are equal.

Hence, number of protons in iron and copper are different. Whereas atomic mass of iron is 55 g/mol and atomic mass of copper is 63 g/mol.

All the atoms consist of three sub-atomic particles that are protons, neutrons and electrons.

Thus, we can conclude that they have different masses, is true about an atom of iron and an atom of copper.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

the answer is d.) potassium