Which of these statements is true regarding the use of testimony on hair samples in courts today? hair samples are replacing dna as an easily available, go-to source for identifying suspects. modern changes in the discipline mean that any police officer can provide testimony on hair samples. hair samples are necessary for most convictions. there's solid research that should lead us to be skeptical of testimony based on hair samples.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.

a chemical change results in a new substance being formed; whereas a physical change will result in a different state of matter

explanation: