Answer:
In a Lewis symbol, the symbol for the element is used to represent the atom and its core electrons. Dots placed around the atom are used to indicate the valence electrons. ... In 1916, Gilbert Newton Lewis, an American chemist, suggested that molecules were formed when atoms shared pairs of outer electrons.
Explanation:
Answer:
The correct answer is - 29.45 / 100 x 25.6 = 7.5392 grams
Explanation:
It is given in the question that in 100 gms of CaSO4 there are 29.45 grams of Ca present and there is 25.6 gram of total CaSO4 sample present, So, to calculate the exact value of calcium in this given sample is:
mass of Ca = total amount of sample*percentage of calcium in sample /100
M of Ca =25.6*29.45/100
M of Ca = 7.5392 grams
Thus, the correct procedure is given by 29.45 / 100 x 25.6 = 7.5392 grams
Answer:
Absorbed, endothermic
Explanation:
Based on the heat of reaction, chemical reactions may be classified as endothermic or exothermic.
In an endothermic reaction, heat is absorbed from the surrounding. As heat is absorbed from the surrounding, the reaction vessel feels cool when touched.
On the other hand, in an exothermic reaction, heat is given out by the system to the surrounding and the reaction vessel feels hot when touched.
Hence the reaction is endothermic and energy is absorbed during the reaction.
Answer:
CO2 consists of individual molecules with one central carbon atom double bonded to two oxygen atoms. Silicon does not form double bonds with oxygen. CO2 is gas but SiO2 is a solid because SiO2 has a giant molecular structure. CO2 has a simple molecular structure, and because of this, CO2 is gas but SiO2 is solid at room temperature.
Answer:
Electrons, with a charge of -1.
Explanation:
The nucleus of the atom is composed of protons and neutrons.
The nucleus is where the bulk of the mass of an atom is found.
Electrons orbit the nucleus in various energy levels.
Protons have a charge of +1, neutrons have no charge, and electrons have a charge of -1.
