Since the beaker was heated we can asume that only magnesium cloride is left in the beaker, therfore the difference between the beaker with magnesium chloride and the empty beaker give the mass of magnisium chloride:
Answer:
3,964 years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of the element is 5,730 years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(5,730 years) = 1.21 x 10⁻⁴ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 1.21 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of the sample ([A₀] = 100%).
[A] is the remaining concentration of the sample ([A] = 61.9%).
∴ t = (1/k) ln([A₀]/[A]) = (1/1.21 x 10⁻⁴ year⁻¹) ln(100%/61.9%) = 3,964 years.
Answer:
The answer is
<h2>720 Joules</h2>
Explanation:
The kinetic energy of a body can be found by using the formula
<h3>
</h3>
where
m is the mass
v is the velocity / speed
From the question
mass = 10 kg
velocity = 12 m/s
Substitute the values into the above formula and solve
That's
<h3>
</h3>
We have the final answer as
<h3>720 Joules</h3>
Hope this helps you
Answer:
1. Flower
- contain the sexual organs of the plant
- attract insect for pollination
- produce fruit carries the seed during fertilization.
2. Leaf
- capture sunlight for photosynthesis
- responsible to make food
- evaporate water molecules
- movement of oxygen and carbon dioxide in and out to plant
3. Stem
- transport water and nutrients from root to leaves.
- support leaves and branches
- in some plants are photosynthetic
4. Root
-provide support by anchoring the plant
- absorb water and nutrients for growth
- store sugars and carbohydrates to perform other functions
Answer:
2 atoms of nitrogen are present.
