Answer is: 2. atomic number.
Atomic number is unique and defines an element. Atomic number (Z) is total number of protons in an atom.
For example, nitrogen atom (N-14) has 7 protons (p⁺), 7 electrons (e⁻) and 7 neutrons (n°). Protons (positive charge) and neutrons are in the nucleus of atom, electrons (negative charge) are bound to the nucleus in spherical shells. Nitrogen is an element with atomic number 7. Mass number (A) is the total number of protons and neutrons in a nucleus. Nitrogen mass number is 14 (A = p⁺ + n°; A = 14).
Answer:
We take 20.0 mL of the 1.0 M fruit drink solution and then add 80.0 mL of water to make 100 mL of a 0.2 M fruit drink solution.
Explanation:
- Using the rule that: the no. of millimoles of a solution before dilution is equal to the no. of millimoles of the solution after the dilution.
<em>(MV) before dilution = (MV) after dilution.</em>
M before dilution = 1.0 M, V before dilution = ??? mL.
M after dilution = 0.2 M, V after dilution = 100 mL.
<em>∴ V before dilution = (MV) after dilution / M before dilution </em>= (0.2 M)(100 mL) / (1.0 M) = <em>20.0 mL.</em>
<em>So, we take 20.0 mL of the 1.0 M fruit drink solution and then add 80.0 mL of water to make 100 mL of a 0.2 M fruit drink solution.</em>
Answer:
<em>K</em><em>+</em><em>Cl</em><em /><em>KCl</em>
Explanation:
because the reaction is between metal Potassium and Non-metal Chlorine
Answer:
Potential energy is energy due to an object's height above the ground.
Potential energy = mass x gravity x height
Kinetic energy is energy due to the motion of the object.
Kinetic energy = 1/2 x mass x velocity²
Answer:
Group 2A — The Alkaline Earth Metals. Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
Explanation:
