The best answer choice is c
Chromium has a total of 28 neutrons. This is found because we subtract the number of protons (the atomic number) from the mass number. 52 minus 24 gives us 28. It also has 24 electrons.
The question was not well arranged above. It has been arranged in the answer below.
Question:
Leon made a study chart about human-induced changes to the environment.
Environmental Changes Caused by Humans
X Y
Results from introducing harmful substances into the environment
Example: oil spill
Results from natural areas being cleared and replaced by human development
Example: deforestation
Which headings best complete the chart?
X: Habitat Destruction
Y: Pollution
X: Long-Term Changes
Y: Short-Term Changes
X: Short-Term Changes
Y: Long-Term Changes
X: Pollution
Y: Habitat Destruction
Answer:
X: Pollution
Y: Habitat Destruction
Explanation:
From the above question, Leon gave us two variables, X and Y.
The human induced changes were divided into two.
1. Results from introducing harmful substances into the environment
Introducing harmful substances into the environment is also called pollution. And we can represent this as X which is the first variable.
2. Results from natural areas being cleared and replaced by human development.
This description given in number two above whereby land areas are been cleared and replaced by human development has a negative effects on the environment because the vegetation which includes the trees are been cut down and living organisms(animals) will go extinct gradually. This act affect the balance of the ecosystem and it can be referred to as the destruction of the habitat of living organisms
Therefore, the correct headings best complete the chart is :
X: Pollution
Y: Habitat Destruction
Answer:- A. 353.5 g
Solution:- The balanced equation is:
From this equation, there is 3:1 mol ratio between calcium chloride and calcium phosphate.
Grams of calcium chloride are converted to moles and these moles are multiplied by the mol ratio to get the moles of calcium phosphate. Finally the moles are multiplied by molar mass to get the grams of calcium phosphate.
Molar mass of 
= 40.078+2(35.45) = 110.978 g per mol
Molar mass of 
= 3(40.078)+2(30.974)+8(16.00)
= 120.234+61.948+128.00 = 310.182 g per mol
let's make the set up using dimensional analysis.
= 
Hence, 353.5 g of calcium phosphate will form and so the correct option is A.
M (NaCl) = n × M = 3.75 × 58.5 =
219.375 g
M (NaCl) = 23 + 35.5 = 58.5 g/mol
