
What is the difference between a quantity and a unit?
Answer:
Physical quantities are a characteristic or property of an object that can be measured or calculated from other measurements. Units are standards for expressing and comparing the measurement of physical quantities. All units can be expressed as combinations of four fundamental units.
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He realized that the physical and chemical properties of elements<span> were related to their atomic mass in a '</span>periodic<span>' way, and </span>arranged<span> them so that groups of </span>elements<span> with similar properties fell into vertical columns in </span>his table<span>.
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The maximum negative displacement of a wave is the same as its amplitude.
As a wave travels through space, its particles are sometimes above the
<em>x</em>-axis (+) and sometimes below it (-).
The maximum displacement from the axis is the <em>amplitude</em> of the wave.
The amplitude of the wave is the <em>same in both the positive and negative directions</em>.
the mass of potassium iodide is 0.360 g
calculation
step 1: write the balanced molecular equation
Pb(NO3)2 (aq) + 2 Ki (s)→ Pbi2(s) + 2KNO3
step 2 ; calculate the moles of Pbi2
moles = mass /molar mass
= 0.500 g / 461 .0 g/mol =0.0011 moles
step 3: use the mole ratio to calculate the moles of Ki
Ki: Pbi2 is 2:1 therefore the moles of ki = 0.0011 x 2/1 = 0.0022 moles
step 4 : find the mass of Ki
mass= moles x molar mass
=0.0022 moles x 166g/mol =0.365 g which is approximate 0.360 g
Answer:Mass of Potassium chloride =1.762g
Explanation:
Mass of empty beaker = 23.100 g
Mass of beaker with Potassium chloride = 24.862g
Mass of Potassium chloride = Final weight - initial weight = Mass of beaker with Potassium chloride - Mass of empty beaker = 24.862-23.100 = 1.762g