Alkali metals, alkaline earth metals, and aluminum all form ions with positive charges equal to the
a. atomic number.
b. group number.
c. period.
d. atomic mass.

b. group number.

Explanation:

The alkali metals are located in group 1 of the periodic table and are the following: lithium, sodium, potassium, rubidium, cesium and francium and form ions with a positive charge because they are in group 1 of the periodic table .

The alkaline earth metals are located in group 2 of the periodic table and are the following: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radius (Ra) and form ions with two positive charges because they are in group 2 of the periodic table.

The aluminum is embedded within the set of other metals and belongs to group 3A and therefore can form an ion with 3 positive charges.

pla·gia·rism

/ˈplājəˌrizəm/

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noun

the practice of taking someone else's work or ideas and passing them off as one's own.

explanation:

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.