I believe it becomes less dense, bc when you heat something it’s molecules spread further apart.
Answer:
A. Whenever the population has increased, steel consumption has increased as well.
Explanation:
Based on the graph of US population and steel consumption, what could have led to the increase in steel consumption seen on the graph is that whenever the population has increased, steel consumption has increased as well.
A critical look at the graph, you will discover that the population and the steel consumption are moving upwards (i.e they are increasing). It's seen that as the population increases, steel consumption increases. This is true because as the population increases, people are building houses, more transportation systems that require steel are being manufactured, more household utensils that are steel products are being fabricated etc; therefore the consumption of steel increases.
Answer : The correct options are,
and 
Explanation :
Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.
Option A reaction : 
It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.
Option B reaction : 
It is an example of single displacement reaction.
Option C reaction : 
It is an example of combination reaction because in this reaction two reactants react to give a single product.
Option D reaction : 
It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.
Option E reaction : 
It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.
Hence, the options B and E are single displacement reactions.
The cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.
<u>Explanation:</u>
The cost of painting the circular traffic sign is given as 3.50 dollar per square feet. The diameter of the traffic sign is 36 inch, then its radius will be
inches.
But as the cost is given in unit of feet, we have to convert the radius from inches to feet.
1 inches = 0.0833 feet
18 inches = 18 × 0.0833 feet
So, the radius of the traffic sign will be approximately equal to 1.5 feet.
The area of the traffic sign will be
square feet.
So, if the cost of painting 1 square feet of traffic sign is 3.50 dollar, then
cost of painting 7.065 square feet of traffic sign = 3.50 × 7.065 = 24.7 dollar.
Thus, the cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.