Answer:
There will be less than 1 gram of the radioactive substance remaining by the elapsing of 118 days
Step-by-step explanation:
The given parameters are;
The half life of the radioactive substance = 45 days
The mass of the substance initially present = 6.2 grams
The expression for evaluating the half life is given as follows;
Where;
N(t) = The amount of the substance left after a given time period = 1 gram
N₀ = The initial amount of the radioactive substance = 6.2 grams
= The half life of the radioactive substance = 45 days
Substituting the values gives;
The time that it takes for the mass of the radioactive substance to remain 1 g ≈ 118.45 days
Therefore, there will be less than 1 gram of the radioactive substance remaining by the elapsing of 118 days.
Answer:
5
Step-by-step explanation:
Think of 5 positive things and 9 negative things.
O O O O O
P P P P P P P P P
5 of the positive things will cancel out 5 of the negative things, leaving behind 4 negative things.
#teamtrees #WAP (Water And Plant)
Answer:
SA =784 pi units ^2
Step-by-step explanation:
The surface area of a sphere is given by
SA = 4 pi r^2
The radius is 14
SA = 4 pi (14)^2
SA =784 pi units ^2
Utilice la división larga. olvidarse de los puntos decimales. para que sea más fácil llevar a cabo. A continuación, poner el punto decimal en el mismo lugar que el dividendo (el número se divide) primero cambie el número estamos dividiendo por un número entero en primer lugar, desplazando el punto de ambos números de decimal a la derecha for example:
6.85/.5=68.5/5
solve
13.7
Decimal places mean we just start counting immediately after the decimal point, so:
2dp: 0.00
1dp: 0.0
Significant figures, we start counting starting at the first non zero number
So we start counting at the 9, therefore:
2sf: 0.00097
3sf: 0.000965
