Answer:
The percentage of the block contains 15% after 60 years.
Explanation:
Step 1: Formula for half-life time
To calculate the half-life time we will use the following formula:
At = A0 * 1/2 ^(x/t)
With At = the quantity after a time t
A0 = The quantity at time t = 0 (start)
x = time in this case = 60 years
t= half-life time = 22 years
Step 2: Calculate the percentage after 60 years
In this case: after 60 years the percentage will be
A0= 10 * 1/2 ^(60/22)
A0 = 1.5
A0 / At = 1.5 /10 = 0.15
0.15 *100% = 15 %
The percentage of the block contains 15% after 60 years.
Explanation:
Most molecules survive for long periods of time at room temperature because at room temperature, they are stable. The room temperature is the temperature between 20-25°C where human beings are the most comfortable.
At the room temperature, most molecules are in their natural physical state without any reason to rearrange their bonds and a times be destroyed. The energy at room temperature is just perfect for bond stability.
Learn more:
ideal gas brainly.com/question/2385746
#learnwithBrainly
number one: when substances like rock and minerals are being physically broken down, its called weathering.
Number two: when particles are carried away to another location exp " a river carrying rocks to an ocean" that's called deposition
Number three: this would also be weathering because it is physically being worn down
Number four: would be a topographic map, because theses maps use lines to study elevation instead of color
Answer:
Alkali metals are highly reactive elements that appear to be silver and they are found in group 1 of the periodic table. It consists of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). As you go further down the group, the more reactive they are. Those elements all react to water and air, so they must be kept in oil to preserve their state.
Answer:
Mass = 24.36 g of N₂
Explanation:
The balance chemical equation for the decomposition of NaNO₃ is as follow;
2 NaN₃ → 2 Na + 3 N₂
Step 1: Find moles of N₂ as;
According to equation,
2 moles of NaNO₃ produces = 3 moles of N₂
So,
0.58 moles of NaNO₃ will produce = X moles of N₂
Solving for X,
X = 3 mol × 0.58 mol / 2 mol
X = 0.87 mol of N₂
Step 2: Calculate mass of N₂ as,
Mass = Moles × M.Mass
Mass = 0.87 mol × 28.01 g/mol
Mass = 24.36 g of N₂
