Hey there!
1.)
The law of conservation of mass states that matter cannot be created or destroyed. This means in a chemical reaction, the products must be equal to the reactants.
2.)
In a balanced chemical equation, there are the same amount of each type of atom, or element, on each side. The products must be equal to the reactants to follow the law of conservation of mass.
3.)
When a chemical reaction occurs, we can see evidence such as bubbles, odor, color change, and heat/light being released. These all are signs that a new substance is being formed.
Hope this helps!
Format Method - Writing the symbol of the cation and then the anion. Add whatever subscripts in order to balance the charges.
Crisscross Method - The numerical value of the charge of each ion is crossed over and becomes the subscripts for the other ion.
Answer : The amount of formaldehyde permissible are,
Explanation : Given,
Density of air =
First we have to calculate the mass of air.
Now we have to calculate the amount of formaldehyde.
Permissible exposure level of formaldehyde = 0.75 ppm =
Amount of formaldehyde in 7.2 g of formaldehyde =
Amount of formaldehyde in 7.2 g of formaldehyde =
Thus, the amount of formaldehyde permissible are,
Answer:
31.1°C
Explanation:
Given parameters:
Temperature = 88°F
The formula of the to convert is:
T°F = T°C - 32 / 1.8 =
Now input the parameters and solve;
T°F =
T°F = 31.1°C
Answer:
The correct answer to this problem is B. 7.0 X 10^-8 meters
Explanation:
To solve this problem, we have to use the following equation:
c = λν, or speed of light = wavelength*frequency
If we substitute in the values we are given by the problem, we get:
3.00 * 10^8 m/s = (4.3 * 10^15 Hz)*(wavelength)
wavelength = 6.98 * 10^-8 m
Since the given value has 2 significant figures, our answer should similarly include two significant figures since the operation in the problem was multiplication.
Therefore, the answer is B. 7.0 X 10^-8 meters.
Hope this helps!