The atomic number is the number of protons meaning that there are 14 protons in an atom of silicon. The mass number is the sum of the protons and neutrons. 28 - 14 = 14. There are 14 protons and 14 neutrons in silicon.
False
The soil is formed from the erosion of surface rocks, not rocks below the soil.
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Answer:
The partial pressure of oyxgen O2 is 606 mmHg
Explanation:
Step 1: Data given
Percentage N2 = 22.8 %
The total pressure = 785.0 mmHg
Step 2: Calculate partial pressures
Partial pressure = percentage * total pressure
Partial pressure N2 = 0.228 * 785.0 mmHg
Partial pressure N2 = 179 mmHg
Step 3: Calculate partial pressure O2
Partial pressure O2 = 785.0 mmHg - 179.0 mmHg
Partial pressure O2 = 606 mmHg
OR (1 - 0.228) * 785.0 = 606 mmHg
The partial pressure of oyxgen O2 is 606 mmHg
Answer:
A. They must be kept separate from moisture and oxygen
Explanation:
Alkali metals refers to a group of chemical elements in the periodic table. It is the common name given to Group 1 elements (excluding hydrogen). They are generally metallic in nature with physical properties like shining lustre, silvery in appearance etc. Alkali metals include lithium, Pottasium, Sodium, Rubidium etc.
One important chemical property of alkali metals is their high reactivity i.e. they tend to react quickly with other substances. For example, alkali metals react vigorously with water to form hydroxides. They also react with oxygen to form oxides. Due to this highly reactive properties, they are kept or stored away from moisture (water) and oxygen (present in air).