This question refers to significant figures. The reason we follow significant figure rules when performing calculations in science is that a calculated answer (which is an extrapolation of a manipulation of measurements) can only be as precise as the least precise measurement recorded. This means if you record measurements to a certain precision, the calculated answer at the most can only match the recorded level of precision as to balance the level of confidence in accuracy before and after calculations.
Answer:
82.5 metres
Explanation:
speed=330m|s
initial time taken =0.5÷2=0.25
distance=speed×time
330m|s × 0.25s = 82.5m
Answer:
a quantitative observation implies that the subject can be measured by quantity, aka amount or in numbers.
Ex 1: adding one gram of salt to one gram of sugar makes two grams of seasoning. in this example, there are individual quantities (1 gram of each) and total quantity (2 grams). this only changes if the substances have a chemical reaction, such as one of them destroying the other, then the weight would change.
Ex 2: a more simple example is the weight of something. putting the substance on a scale (one specifically for whatever you are measuring, whether it be liquid or solid) is the best way to determine its quantity.
Half life of a radio-active material is refereed to the time required for reducing its activity to 50 %.
Now, when I-131 passes 1st half life, it's activity will reduce to half i.e. 50%
When, I-131 passes 2nd half life, activity of I-131 will be reduced to 25%
On passing, 3rd half-life, percent activity of the I-131 <span>remaining will be 12.5 %.</span>
Calculate the number of molecules present in 3.50 mol feo2. 2.11 x 1024 molecules 2.107 x 1023 molecules 3.50 x 1023 molecules <u>3.5*(6.02*10^23)=2.107*10^24 molecules</u>
<h3>What is
molecules?</h3>
A molecule is the smallest unit of a substance that keeps its content and properties. It is made up of two or more atoms that are joined together by chemical bonds. Chemistry is built on molecules. The element symbol and a subscript indicating the number of atoms are used to identify molecules.
The fundamental building block of an element is an atom. They are made up of an electron-surrounded nucleus. An atom is considered to have valence electrons if its electron shell is not completely complete. A chemical (covalent) connection is created and a lower energy state is entered when two or more atoms join forces to share outer shell valence electrons. In an exothermic reaction, energy is released as atoms bond.
To learn more about molecules from the given link:
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