Answer:
9 (1-2x²)
Explanation:
The given expression is:
30 - 9x²*2 - 21 - 4 + 4
The first step is to compute the multiplication. This will give:
30 - 18x² - 21 - 4 + 4
Then, we will add like terms as follows:
(30-21-4+4) - 18x²
= 9 - 18x²
Finally, we can take the 9 as a common factor from both terms, this will give:
9 (1-2x²)
Hope this helps :)
Explanation:
When there occurs sharing of electrons between two chemically combining atoms then it forms a covalent bond. Generally, a covalent bond is formed between two non-metals.
An ionic bond is defined as the bond formed due to transfer of one or more number of electrons from one atom to another. An ionic bond is always formed between a metal and a non-metal.
Every atom of an element will have orbitals in which electrons are found. These orbitals are known as energy level.
A molecule is defined as the smallest particle present in a substance or atom.
A metallic bond is formed due to mobile valence electrons shared by positive nuclei in a metallic crystal.
Thus, we can conclude that given statements are correctly matched as follows.
1). a chemical bond formed by the electrostatic attraction between ions - ionic bond
2). a chemical bond formed by two electrons that are shared between two atoms - covalent bond
3). the orbitals of an atom where electrons are found - energy level
4). the smallest particle of a covalently bonded substance - molecule
5). a bond characteristic of metals in which mobile valence electrons are shared among positive nuclei in the metallic crystal - metallic bond
Answer: The density of chloroform is 1.47 g/mL
Explanation : Given,
Volume = 40.5 mL
Mass of cylinder = 85.16 g
Mass of cylinder and liquid = 145.10 g
First we have to calculate the mass of liquid (chloroform).
Mass of liquid = Mass of cylinder and liquid - Mass of cylinder
Mass of liquid = 145.10 g - 85.6 g
Mass of liquid = 59.5 g
Now we have to calculate the density of liquid (chloroform).
Formula used:
Now putting g all the given values in this formula, we get:
Therefore, the density of chloroform is 1.47 g/mL
– liquids, solids or gases – are made up of atoms and molecules that are in constant motion.<span> The theory also states that collisions between atoms and molecules are elastic</span>