The applicable answers include;
- Movement of galaxies
- The Sun's chemical makeup.
The speed of light and the duration it takes to travel between various points in the universe allows scientists to estimate the ages of distant stars and galaxies. Due to the expansive scale of the universe, it takes years for light to journey from one galaxy to another. Understanding the light's speed and the time taken for it to travel from a remote celestial object, alongside geometric calculations and brightness assessments, enables us to approximate the celestial body's age. A star's age can also be ascertained through its elemental composition. Young stars predominantly consist of lighter elements like helium, while older stars contain a greater proportion of heavier elements such as iron, resulting from the fusion of lighter elements into heavier ones at the core of the sun.
The applicable answers include;
- Radiometric dating of rocks
- Fossil evidence
- Gradual geological processes
Radiometric dating refers to employing the half-life of naturally occurring decaying elements like carbon-14 to determine the age of fossils or rocks. The slow creation of rocks, including the lithification of sedimentary rock or the transformation of rocks, is likewise used to estimate the Earth's age by examining the developmental stage of the rocks and extrapolating their age through calculations.
Venus: very few surface winds, clouds of sulfuric acid, runaway greenhouse effect.
Earth: atmosphere mainly consists of nitrogen along with a UV-absorbing stratosphere
Mars: atmosphere with extremely low density and global dust storms.
Answer:
The troposphere is regarded as the most crucial layer of the atmosphere. It is the lowest atmospheric layer, averaging 13 km in height. Its thickness ranges from 8 km to 18 km, being thickest at the equator and thinnest at the poles. Atmospheric phenomena like rain, winds, and clouds all occur within this layer. Approximately 80% of the Earth's atmospheric mass is found in the troposphere, which consists mainly of nitrogen (78%) and oxygen (21%), along with minor traces of other gases. Hence, the troposphere plays a vital role in sustaining life on Earth by facilitating cloud formation, precipitation, and regulating the planet's temperature.
Response:
I’m leaning towards b, but d could also be a possibility; it’s hard to determine given it’s a screen capture.
