Answer:
each group of the periodic table.
example group 7 - fluorine, chlorine, bromine, iodine, astatine, tennessine
There are three perfect squares in a standard die; 1, 2, 4. If there is two standard dies, then the probability of getting a perfect square is 1/3 x 1/3 = 1/9.
There are 4 numbers less than 5 in a standard die, making it 1/4 x 1/4=1/16.
Oxygen
For metals, reactivity increases as we move through the elements in the period table from top to bottom, and left to right. In contrast, for nonmetals, reactivity increases as we move through the elements in the periodic table, as we move from bottom to the top, and right to left.
Group 16 on the periodic table is also called the oxygen family or chalcogens. It includes the following elements from top to bottom: Oxygen, Sulfur, Selenium, Tellurium, and Polonium. Of these, only Oxygen, Sulfur, and Selenium are nonmetals. Since reactivity of nonmetals increases going up the periodic table, oxygen is therefore the most reactive nonmetal in the group. Shown in the figure below is the reactivity trend in the periodic table.
Answer:
NH₃
M = n/V(L)
0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)
Explanation:
Step 1: Given and required data
- Volume of solution (V): 375. mL
- Molar concentration of the solution (M): 2.25 M
- Chemical formula for ammonia: NH₃
Step 2: Calculate the moles (n) of ammonia (solute)
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V(L)
n = M × V(L)
n = 2.25 mol/L × 0.375 L = 0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water. The goal is to produce water fit for a specific purpose. Most water is disinfected for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, including fulfilling the requirements of medical, pharmacological, chemical and industrial applications. The methods used include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultra violet light.