Answer: D. Albedo
Explanation:
The proportion of total light incident on surface that is reflected back is called its albedo. These are typical features of an astronomical body. It is a dimension less quantity and its value ranges from 0 to 1. Light surfaces reflect larger amount of light than dark surfaces. This feature can be clearly seen on planet Mars and the Moon.
Thus, the fraction of the total radiation that is reflected by any surface is called its <u>Albedo.</u>
Answer : The number of half-life periods will be, 3
Explanation : Given,
Initial amount of lead = 10 kg
Amount of lead after decay = 1.25 kg
Half-life = 22 years
Formula used :
where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives
= half-life
Now put all the given values in the above formula, we get:
Thus, the number of half-life periods will be, 3
H = mc∆T
where, H=heat energy
c = SHC
H = 2*921*(40-20)
H = 36840J
H = 36.84KJ
The energy transferred to it is 36.84KJ
Answer:
<h2>1) 1.30g</h2><h2>2) 3 sf</h2><h2>3) 5.66 grams</h2>
Explanation:
1) Significant figure means the amount of figure we are interested in. Note that 0 is insignificant. For example 30 is a one significant figure i. e the only figure of interest is 3.
Given the figure 1.296 g, as we can see, there are initially for figures in the value. This means we are to eliminate one to make it 3. To do that we will remove the 6 at the back by round it up to 1 and add it to the value of 29 preceding it to give 30. The figure will become 1.30 (to 3sf).
<em>Note that only values greater than 4 are rounded up to 1 and added to the preceding value</em>
2) Given the figure 2020, the number of significant figures present is 3 significant figure. Note that all zeros at the end of a value are considered insignificant hence the only significant value here is 202 (which is 3 sig fig.)
3) For the figure 5.658, the value to 3sf is 5.66 (Note that the value of 8 at the end is rounded up to 1 and added to 65 to make it 66). This is as explained in the first answer above.
