The thing that two changes have in common that snails growing shells and rust forming on a bicycle frame is option D. Both are caused by cooling.
<h3>How come snails develop shells?</h3>
Calcium carbonate is said to be the material that makes up the shell. The snail's shell expands as it grows to accommodate its growing body. Snails and slugs are also members of the mollusc family of creatures.
Therefore, note that air that has been mixed with the metal can make rust to develop. and as such, option D. Both are caused by cooling. is correct.
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What do these two changes have in common? snails growing shells rust forming on a bicycle frame Select all that apply.
A. Both are only physical changes.
B. Both are caused by heating.
C. Both are chemical changes.
D. Both are caused by cooling
Answer:
Explanation:
In CF4 and NF3, the valence electron groups on the central C and N atoms have a tetrahedral arrangement. The shapes of the molecules are determined by the number of bonding and nonbonding of electrons: since CF4 has four bonded atom(s) and zero lone pair(s) of electrons, the shape is tetrahedral.
<u>Answer:</u> The weak bond having slightly positive region and a slightly negative region is polar covalent bond.
<u>Explanation:</u>
Covalent bond is defined as the bond which is formed by the sharing of electrons between the atoms. <u>For Example:</u> HCl, 
etc..
They are of two types:
- <u>Polar covalent bond:</u> This bond is formed when difference in electronegativity between the atoms is present. When atoms of different elements combine, it results in the formation of polar covalent bond.
In this bond, a dipole is created. More electropnegative atom will have a slight negative charge and less electronegative atom will have a slight positive charge. For Example: 
etc..
- <u>Non-polar covalent bond:</u> This bond is formed when there is no difference in electronegativity between the atoms. When atoms of the same element combine, it results in the formation of non-polar covalent bond. For Example:
etc..
Hence, the weak bond having slightly positive region and a slightly negative region is polar covalent bond.
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