Answer:
Hydrogen and helium compounds.
Explanation:
We know that the solar System was formed around <u>4.6 billion years ago, </u>due to the gravitational collapse of a giant interstellar molecular cloud.
This cloud is a type of interstellar cloud and its density and size permit the formation of molecules, most commonly molecular hydrogen.
Therefore the principal substances were found before planets began to form are hydrogen and helium compounds, besides Rocks, metals, most of them in gaseous form.
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<span>...a concordant intrusion.
In geology, "concordant" means the same as "sill" -- or, an intrusion that has gotten in between older layers of rock (or even beds of volcanic lava). An intrusion with boundaries parallel to layering in surrounding rocks suggests this, meaning it is considered to be a concordant intrusion.</span>
Answer:
Radio waves
Explanation:
The electromagnetic spectrum includes all different types of waves, which are usually classified depending on their frequency. Ordering them from the highest frequency to the lowest frequency, they are:
- Gamma rays
- X-rays
- Ultraviolet
- Visible light
- Infrared radiation
- Microwaves
- Radio waves
Radio waves are the electromagnetic waves with lowest frequency, their frequency is lower than 300 GHz (
) and therefore they are the electromagnetic waves with lowest energy (in fact, the energy of an electromagnetic wave is proportional to its frequency). They are generally used for radio and telecommunications since this type of waves can travel up to long distances.
Answer:
Explained
Explanation:
Metals are good conductors of electricity because they contain free electrons in their atoms. The outer shell of atom's of metal have free electrons. These free electrons are responsible of electrical conductivity of metals. These electron are not bounded by the attraction forces of the nucleous. They are free to wonder in lattice of positive ion and thus allow electrical conductivity.
Answer:
False
Explanation:
In addition to stars, our galaxy contains abundant diffuse matter that is distributed throughout its volume and constitutes what we call the interstellar medium. This medium plays a fundamental role in the life cycle of the stars, since it is where the matter from which they are born resides, and it is the place to which it returns when the stars expel their outer layers at death.
The interstellar medium is a complex environment. <u>Its matter is </u><u>not </u><u>distributed uniformly</u>, but consists of different phases with temperatures ranging from a few degrees Kelvin (near absolute zero) in the areas of star formation to the millions of degrees Kelvin observed in supernova remnants. The densities of interstellar matter also vary orders of magnitude according to the phase, but they are always so low that they rival those that can be achieved in the best vacuum chambers of terrestrial laboratories. Depending on the density and temperature conditions, interstellar matter is in a molecular, atomic, or ionized state, although the state is not permanent, since matter circulates between the different phases in a continuous cycle of evolution on a galactic scale.
Due to the very different characteristics of its multiple phases, the interstellar medium has to be studied using various observational techniques and different types of telescopes. The coldest components of the interstellar medium do not emit visible light, and require the observation of telescopes sensitive to the weak emission of radio waves that this material produces. Using different radio telescopes, such as the 40-meter diameter of the Yebes Observatory, which the Institute of Radio Astronomy Millimeter, to which the IGN belongs, has in Grenoble and Granada, or the recently opened Atacama Large Millimeter / submillimeter Array in the Atacama desert in Chile, astronomers from the National Astronomical Observatory contribute to characterize the physical and chemical properties of the molecular clouds where stars are born and of the circumestellar shells produced by the stars in the last stages of their lives . The study of these regions is helping to complete our knowledge of the most unknown phases of the complex life cycle of stars.
