Which statement correctly compares an atom of an alkali metal with an atom of the alkaline earth metal next to it on the periodic table?

the alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.
the alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion.
the alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal.
the alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.

The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.

Explanation: Group 1 elements are called as alkali metals and group 2 elements are called as alkaline earth metals.

For example, Li is an alkali metal and Be is an alkaline earth metal.

Lithium(Li) has an atomic number of 3 and the electronic configuration is:

Li:

Thus lithium has to lose 1 electron and acquire 1+ charge to attain nearest noble gas configuration.

Berrylium(Be) has an atomic number of 4 and the electronic configuration is:

Be:

Thus berrylium has to lose 2 electrons and acquire 2+ charge to attain nearest noble gas configuration.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.