Which atom in the ground state has an outermost electrons in the shells of a calcium energy

The answer is Cs, no. 2.

Cesium (Cs) is an element which has an outermost electron with most energy in the ground state. 

 Cesium (Cs), Lithium (Li), Potassium (K), and Sodium (Na) are elements which belong to the group 1 family, the alkali metals. Each has a valance of 1 and wants to release/ lose this e- (electron) to be isoelectronic with the nearest noble gas. Based on the periodic trends, an atom’s radii will raise going down a group.  

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answer: option (4) is the correct answer.

explanation:

areas which are at low altitudes and near the equator tend to receive direct sunlight from the sun. hence, heat energy or radiations from the sun make these areas warmer and they have warmest water.

whereas areas which are at high altitudes and away from the equator do no receive direct sunlight. hence, no direct contact from the sun makes these regions colder and thus, they have colder water.

thus, we can conclude that the statement areas at low latitudes near the equator have the warmest water because they receive the most direct sunlight best explains the relationship between an area's geography and the temperature of its surface water.