Answer:
Requirements for a correctly written chemical equation are reactants and products, their formula and valency
Explanation:
Formula of the given compound are -
1 - Potassium Hydroxide - 
2 - Calcium Nitrate - 
The requirements for a correctly written chemical equation are -
- Identifying reactants and products
- Formula of reactants and products
- Valency of elements
Example of word equation, formula equation, and chemical equation is as follows -
Aluminium + iron9(III)oxide ⇒ aluminium oxide + iron (word equation)
+ 
⇒ 
+ 
(formula equation)
+ ⇒ + 
(chemical equation)
The answer is <span>B. element.
An element is composed of only one kind of atom and cannot be separated into simpler substances. Oxygen (O) is the element.
A compound is a substance composed </span><span>of two or more <em>different </em>atoms chemically bonded to one another, for example, water (H</span>₂<span>O) consists of 2 atoms of hydrogen (H) and 1 atom of oxygen (O), so it is the compound.
A mixture consists of two or more substances that are not chemically combined. Solutions and colloids are mixtures.</span>
Answer : The final temperature of the mixture is 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of iron = 
= specific heat of water = 
= mass of iron = 39.9 g
= mass of water = 
= final temperature of mixture = ?
= initial temperature of iron = 
= initial temperature of water = 
Now put all the given values in the above formula, we get
Therefore, the final temperature of the mixture is
a.True.
The ordely geometric arrangement of atmos is called a crystalline solid.
Answer: 
Explanation:
Given : Sample size : n= 30 , it means it is a large sample (n≥ 30), so we use z-test .
Significance level : 
Critical value: 
Sample mean : 
Standard deviation : 
The formula to find the confidence interval is given by :-
i.e. 
i.e. 
Hence, the 95% confidence interval for the mean mpg in the entire population of that car model =
