Select all the answers that apply. Types of evidence that astronomers use to estimate the age of the universe and stars include .

movement of galaxies
molecular clocks
fossil evidence
chemical composition of the Sun
radioactive dating of rocks

The answer that apply;

Movement of galaxies

Chemical composition of the Sun.

Light and the time it takes to traverse between particular points in the universe is used to calculate the age of distant stars and galaxies. Because of the vast nature of the universe, light takes earth years for it to travel from one galaxy to another. By knowing the speed of light and the amount of time taken for the light to travel from a distant celestial body, and use of geometric calculations, and brightness measurements we can tell in approximation the age of the celestial body. The age can also star can also be determined by their composition. Youg stars are mainly found have lighter elements such as helium. As they age, they have more composition of heavier elements such as iron. This is due to the fusion at the core of the sun that fuses lighter elements to heavier elements.

The answers that apply are;

radiometric dating of rocks

fossil evidence

gradual processes of rock

Radiometric dating means the use of half-life of naturally decaying elements such as carbon-14 to tell the age of a fossil or rock. The gradual formation of rocks such as lithification of sedimentary rock or metamorphosis of rock is also used to calculate the age of the earth by studying the stage in the process in which the rocks are in and extrapolating the age using calculations.

Explanation:

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.