Answer:
The answer is Bob
Explanation:
The science exist to kinds of measurements base units and derive units of measurement.
Base units are the ones that measure: length, mass, time, electric current, temperature, luminous intensity and amount of substance.
Derivative units of measurement are obtain when we combine the base units.
Know from your question
Bob measures length is a base unit
Jill measures density is a derivative unit, is the combination of mass and volumen
Kim measures mass is a base unit
Steve measures brightness is a base unit.
Answer
Rotating
Explanation:
The Earth is always being pulled towards the Sun by gravity.
The Earth is not moving fast enough to "escape" the Sun's gravity and leave the solar system, but it is going too fast to be pulled into the Sun. Therefore, it keeps going around and around( roating)- orbiting the Sun.
You will need a periodic table to help you answer this problem. The atomic numbers are arrange from lowest to highest in the periodic table. You can locate element number 55 to be Cesium with an atomic weight of 132.905 amu. So, you start from element 56. The following elements are:
56 Barium 137.328 amu
57 Lanthanium 138.905 amu
58 Cerium 140.116 amu
59 <span>Praseodymium 140.908 amu
60 Neodymium 144.243 amu
Neodymium is already greater than 144 amu. Therefore, these elements only include Barium, Lanthanium, Cerium and Praseodymium.</span>
Answer: (2) decreasing the concentration of HCl(aq) to 0.1 M
Explanation: Rate of a reaction depends on following factors:
1. Size of the solute particles: If the reactant molecules are present in smaller size, surface of particles and decreasing the size increases the surface area of the solute particles. Hence, increasing the rate of a reaction.
2. Reactant concentration: The rate of the reaction is directly proportional to the concentration of reactants.
3. Temperature: Increasing the temperature increases the energy of the molecules and thus more molecules can react to give products and rate increases.
(1) Increasing the initial temperature to 25°C will increase the reaction rate.
(2) Decreasing the concentration of HCl(aq) to 0.1 M will decrease the reaction rate due to lesser concentration.
(3) Using 1.2 g of powdered Mg will increase the reaction rate due to large surface area.
(4) Using 2.4 g of Mg ribbon will increase the reaction rate due to high concentration of reactants.
Answer:
• Molecular mass of Iron (III) tetraoxide
[ molar masses: Fe → 56, O → 16 ]
