Answer:
Explanation:
In the upper thermosphere, atomic oxygen (O), atomic nitrogen (N), and helium (He) are the main components of air.
Answer:

Explanation:
Given that,
The mass of a sample, m = 16.7 grams
Volume of the sample, V = 4.4 cm³
We need to find the density of the metal sample.
Density = mass/volume
Substituting all the values,

So, the density of the metal sample is
.
Answer:
Individuals who live around the woodland regions and rely on the backwoods assets for food. The Public authority Timberland Office, which possesses the backwoods land. The industrialists utilize woodland items for different modern purposes. The fans for the protection of untamed life and nature.
Explanation:
The correct answer is d. 8p+; 9n; 10e−
Oxygen exists in three isotopes ¹⁶O, ¹⁷O and ¹⁸O. The atomic number of oxygen is 8. It means its nuclei has 8 protons. The given is oxide⁻² anion. This means it has gained 2 electrons. Thus, oxide anion have 8 protons and 10 (8+2) electrons. The number of neutrons depends on the isotope, in this question mass number is given¹⁷O. The mass number is the sum of the protons and neutrons in the nucleus. Hence, number of neutrons oxide anion will be 17-8 = 9 neutrons.