<span>D. The screw changes the direction of a force - it converts linear force into rotational force. It also reduces the force required - the closer the threads, the smaller the input force required to get the same output force.</span>
Answer:
positive charge
Explanation:
Protons are positively charged
The Lewis formula refers to a diagram showing the distribution of electrones and in case of a molecule it also shows the bonds.
The structural formula on the other hand is a representation of the molecular structure that shows all the atoms that form the molecule, arranged in a three dimentional space,
In this case we have the hydrogen ion, which is the simpliest case we can have.
Hydrogen ion is the hydrogen atom possitively charged as it has lost his electron. Therefore the structural formula is simply the following:
The Lewis formula is also very simple as this ion has no electrons and has no bonding to other atoms:
The question is incomplete, here is the complete question:
Write a balanced chemical equation for each single replacement reaction that takes place in aqueous solution. write no reaction if a reaction does not occur
1.) Zn + PbCl₂
2.) Cu + Fe(NO₃)₂
<u>Answer:</u>
<u>For 1:</u> The reaction does occur.
<u>For 2:</u> The reaction does not occur.
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

For the given options:
Zinc is more reactive than lead as it lies above in the series. So, it will displace lead from its chemical equation.
The chemical equation for the reaction of zinc and lead chloride follows:

Copper is less reactive than iron as it lies below in the series. So, it will not displace iron from its chemical equation.
The chemical equation for the reaction of copper and iron (II) nitrate follows:
