Although scientists are unable to explore the Sun’s layers directly with instruments, they can measure the change in the speeds of the surface layers and the temperature of those layers from Earth. Using this data, scientists have created models of the Sun and we now know that the sunspots that form on the surface are the areas of coolest temperature for this star. At the sunspots, temperatures are merely 3700 Kelvin (K). What does this indirect information about the Sun confirm? The Sun has a structure similar to Earth's structure. Storms form on the surface of the Sun, similar to the atmosphere of Earth. The Sun's photosphere has properties of a solid, similar to the crust of Earth. Convection occurs in parts of the Sun, similar to convection in the mantle of Earth.

a chemical reaction

explanation:

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

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.