Answer:
1992 (Early 1990s)
Explanation:
First of all, i would like to define an extrasolar planet as a planet that orbits a start that is not our own.
The first confirmed detections of extrasolar planets occured in the early 1990s (specifically 1992, some say 1995). The name of the first extrasolar planet is widely believed to be called Dimidium or 51 Pegasi b.
Extrasolar were searched by monitoring stars for slight dimming that might occur as unseen planets pass in front of them.
<u>Answer:</u>
The modern atomic theory has given by "John Dalton and framed postulates".
<u>Explanation:</u>
The fundamental role of atoms in chemistry is established by the modern theory of atoms mentioned in 1808 for the first time by an English scientist named John Dalton. This consists of three sections such as all matter is composed of atoms, atoms of the same element are the same while atoms of different elements are different, atoms combine to form compounds in full-number ratios.
The unique characteristic of the "number of protons" is that all atoms of the same compound share. While the atoms of the same element i.e having a similar number of protons can have different numbers of neutrons and such elements are called isotopes.
Nitrogen is a crucially important component for all life. It is an important part of many cells and processes such as amino acids, proteins and even our DNA. It is also needed to make chlorophyll in plants, which is used in photosynthesis to make their food.
explanation
a=average velocity/average time
average velocity=0.0+1.2+2.4+3.6/4
average velocity=7.2/4
average velocity=1.8 m/s
average time=0.0+3.0+6.0+9.0/4
average time=18/4
average time=4.5 s
a= average velocity/average time
a=1.8/4.5
a=0.4 m/s²
