Answer:

Explanation:
We are asked to find the density of a metal. Density is the mass per unit volume. It is calculated by dividing the mass by the volume.

The mass of the metal sample is 24.64 grams and the volume is 5.91 milliliters. We can substitute these values into the formula.

Divide.

The mass measurement has 4 significant figures the volume measurement has 3 significant figures. Our answer for density must match the least number of significant figures, which is 3.
For the number we calculated, that is the hundredth place. The 9 in the thousandth place tells us to round the 6 up to a 7.

The density of this metal is approximately <u>4.17 grams per milliliter.</u>
Answer:
1.9×10^20
Explanation:
ϕ = number of reaction events /number of photons absorbed
ϕ= 0.26
Energy= power× time
885×10^-3×10×60= 531J
But E= nhc/λ
n= number of photons
h= planks constant
c= speed of light
λ= wavelength
n= Eλ/hc
n= 531×280×10^-9/6.6×10^-34 ×3×10^8
n= 7.5×10^20
Therefore
From
ϕ = number of reaction events /number of photons absorbed
Number of reaction events= 0.26×7.5×10^20
= 1.95×10^20
The answer is the el second one since it is a physical change
Answer:
A good society has a transparent talk, they share all matters related to the society, hence everyone knows what's going on. This is why collectiveness leads to a good society.
If my answer helped, kindly mark me as the brainliest!!
Thank You!!