Answer:
the first one is just water and the second one is gas
Explanation:
Answer:
2
Explanation:
the pH of the strong acid solution will be
pH = -log[H+] = -log[0.01] = 2
<h2>
Answer:</h2>
Hey,
<h3><u>
QUESTION)</u></h3>
The mass of 6,022 × 10²³ molecules of a substance is called its molar mass.
- In fact this number represents the Avogadro Constant characteristic of the number of entities contained in a mole.
Answer:
Anaesthesia & Intensive Care Medicine
Volume 6, Issue 9, 1 September 2005, Page 294
Force, mass and acceleration
Author links open overlay panelPhilDalrympleaRichardGriffithsb
https://doi.org/10.1383/anes.2005.6.9.294
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Abstract
Force, mass and acceleration are everyday words but often used inaccurately. Force is a physical influence, which when applied to an object causes it to accelerate in the direction from which it was applied. Mass is the amount of matter in an object and is expressed in kilograms. Acceleration is the rate of change of velocity of an object in the same straight line of the unbalanced force. When forces become balanced, there is no net force and therefore no movement. Newton’s second law links these three terms and concerns the effect that an unbalanced force has on the motion of an object. It states that the rate of change of velocity of an object is directly proportional to the force applied and takes place in the direction of the force. It is summarized by the equation: Force (N) = mass (kg) × acceleration (m/s2). Thus, an object of constant mass accelerates in proportion to the force applied. Gravity is the variable force of attraction between any two objects. All matter possesses gravitational ‘pull’ towards other matter. The amount of gravity between two objects is dependent on their mass and the distance between their centres. The word ‘weight’ in its proper context refers to the downward vertical force exerted on an object as a result of the earth’s gravity. An object with greater mass is therefore subjected to a greater gravitational force (i.e. it has greater weight).
Answer:
Explanation:
The<em> half-life </em>time of a radiactive isotope (radioisotope) is a constant value, meaning that the amount of the radioisotope that decays will be (1/2) raised to the number of half-lives passed.
Naming A₀ the initial amount to the radioisotope, you can build this table to find the amount left.
Number of half-lives amount of radiosotope left
0 A₀
1 (1/2) × A₀
2 (1/2)×(1/2)×A₀ = (1/2)² × A₀
3 (1/2)³ ×A ₀
4 (1/2)⁴ × A₀
n (1/2)ⁿ × A₀
Now calculate the number of half-lives the strontium-90 sample has passed after 100 years:
- n = 100 years / 28.1 years ≈ 3.5587
Hence, the amount of strontium-90 is:
In percent, that is:
Rounding to two significant figures, that is 8.5%.
<u>Conclusion</u>: <em>The percent of strontium-90 left after 100 yeaers is 8.5% </em>(choice number 4).
