The correct answer is D.
Echo refers to the sound that is heard when a sound wave is reflected back from a surface. An echo sound is made when a sound wave traveled through the air, hit a hard surface and get reflected back. Generally, hard surfaces reflect sound wave while soft surfaces absorb sound waves. Reflected sound waves are used in application of some devices that are used in range and direction finding.
Answer:
Amount of excess Carbon (ii) oxide left over = 23.75 g
Explanation:
Equation of the reaction: Fe₂O₃ + 3CO ----> 2Fe + 3CO₂
Molar mass of Fe₂O₃ = 160 g/mol;
Molar mass of Carbon (ii) oxide = 28 g/mol
From the equation of reaction, 1 mole of Fe₂O₃ reacts with 3 moles of carbon (ii) oxide; i.e. 160 g of iron (iii) oxide reacts with 84 g (3 * 28 g) of carbon (ii) oxide
450 g of Fe₂O₃ will react with 450 * 84/180) g of carbon (ii) oxide = 236..25 g of carbon (ii) oxide
Therefore the excess reactant is carbon (ii) oxide.
Amount of excess Carbon (ii) oxide left over = 260 - 236.25
Amount of excess Carbon (ii) oxide left over = 23.75 g
<span>The ionic charge of Calcium (Ca) in calcium carbonate (CaCO3) is 2+. CaCO3 has a neutral ionic charge sin CO3 has a 2- charge.</span>
ans A. 13 to 3
solution:
Total puppies for sale=6
Total puppies left = 2
hence total puppies sold= 6 - 2 = 4
cost of a puppy= $ 104
so cost of 2 puppies = 104 x 4
=416$
Now for kittens:
Total kittens for sale = 12
Total kittens left = 8
hence total kittens sold=12 - 8 =4
cost of a kitten = $24
so cost of 4 kittens= 24x 4=96$
Now ratio of sales of puppies to kittens = 208$/96$
= 13/3 or 13:3 or 13 to 3
I hope this explanation will help you to understand this problem
Answer: The Sun Could Be Seen Once during the year when north of the equator.