Noble gases' outer shells are already filled with 8 electrons (other than He, which has 2, but is still filled and stable). Atoms bond with other elements to fill their outer shell, but they don't need to do that and are already stable.
Lysosome: only ones that break down old cell parts<span>
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Answer: The ratio of carbon dioxide molecules to oxygen molecules is 20 :31
Explanation:
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced combustion reaction is,:
Thus the ratio of carbon dioxide molecules to oxygen molecules is 20 : 31
There are types of lens; concave and convex lens.
The concave lens is a lens which has an inward curve in the middle, that is, the edges of the curve are thicker than the center of the lens, because of this, any light that enter the lens will spread out [diverge]. An image will look smaller and upright when viewed by a concave lens. Image formed by concave lens are usually VIRTUAL.
A concave lens will produce a real image ONLY if the object is located beyond the focal point of the lens.
A convex lens is a converging lens, this is because, the center of the lens is thicker than its edges. Any ray of light that passes through the lens will converge at the middle of the lens at point called principal focus. A convex lens produce a VIRTUAL image when the object is placed infront of the focal point. The virtual image formed is always magnified and upright.<span />
Answer:
% composition O = 19.9%
% composition Cu = 80.1%
Explanation:
Given data:
Total mass of compound = 3.12 g
Mass of copper = 2.50 g
Mass of oxygen = 3.12 - 2.50 = 0.62 g
% composition = ?
Solution:
Formula:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition Cu = (2.50 g / 3.12 g)×100
% composition Cu = 0.80 ×100
% composition Cu = 80.1%
For oxygen:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition O = (0.62 g / 3.12 g)×100
% composition O = 0.199 ×100
% composition O = 19.9%
