Answer: Chemical composition modification (or, physical signal would be color).
Answer:
See below!
Explanation:
A. The picture of the graph is attached. You can tell the amount of protons in an element by looking at the periodic table. The elements are ordered by the number of protons in an element.
B. Carbon and silicon are at the peaks of the chart. The peak is the highest point in a graph.
C. The elements belong to the non-metal group.
D. The halogens are non-metals, and their vapors are colorless.
The halogens are toxic to humans.
Halogen molecules are made of two atoms; they are diatomic.
Halogens react with non-metals to form crystalline compounds that are salts.
The halogens get less reactive going down the group on the periodic table.
Halogens can bleach vegetable dyes and kill bacteria.
E. The picture of the table is attached. To figure which numbers to put where, you need to pay attention to the other numbers. The halogens follow a trend with each of these properties. You have to put in the numbers that fit in among the other numbers.
Answer: the line Spectra of hydrogen lies between the ultra-violet, visible light and infra-red of the electro magnetic spectrum
Explanation:
Electromagnetic radiation spans an wide range of wavelengths and frequencies. This range is called the electromagnetic spectrum. The electromagnetic spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The 7 regions includes; radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.
lower-energy radiation, such as radio waves, is expressed as frequency while microwaves, infrared, visible and UV light are usually expressed as wavelength and finally, higher-energy radiation such as X-rays and gamma rays, is expressed in terms of energy per photon.
Therefore, hydrogen lies between the ultra-violet, visible light and infra-red region of the electro magnetic spectrum.
1 mole Hg ---------------- 6.02x10²³ atoms
?? ------------------------- 1.30 x10⁷ atoms
1.30x10⁷ x 1 / 6.02x10²³ =
= 1.30x10⁷ / 6.02x10²³ => 2.159x10⁻¹⁷ moles
hope this helps!