Answer:
a small medical thermometer with a short but finely calibrated range, for taking a person's temperature.
Answer:
The most notable of these are known as the "six simple machines": the wheel and axle, the lever, the inclined plane, the pulley, the screw, and the wedge, although the latter three are actually just extensions or combinations of the first three.
Answer:
This question appear incomplete
Explanation:
This question appear incomplete because an equation to show the production of sodium chloride from calcium chloride should have been illustrated. However, if the balanced chemical equation showing sodium chloride (NaCl) been a product of a reaction involving calcium chloride (CaCl₂) as a reactant (shown below) is to be used, then we start by writing a complete balanced chemical equation
CaCl₂ + Na₂CO₃ ⇒ CaCO₃ + 2NaCl
From the equation above, it can be deduced that 1 mole of CaCl₂ is required to produce 2 moles of NaCl, thus how many moles of CaCl₂ will be required to produce 6.5 moles of NaCl.
1 mole of CaCl₂ = 2 moles of NaCl
? moles of CaCl₂ = 6.5 moles of NaCl
cross multiply
? moles of CaCl₂ = 6.5 × 1/2
? moles of CaCl₂ = 3.25 moles of CaCl₂
3.25 moles of CaCl₂ will be needed to produce 6.5 moles of NaCl
Answer:
C. Scientists accepted the model at first but later rejected it.
Explanation:
Scientists accepted the model at first because it explained the hydrogen emission spectrum.
However, with the development of quantum mechanics, scientists had to modify the model (not reject it).
Electrons still had specific energies, but they no longer travelled in fixed orbits.
Instead, electrons had a probability of being found in a given region of space.
Answer:
A. 140,800 J
Explanation:
Specific heat of a material is defined as the amount of energy required to increase in 1°C 1kg of the material. <em>For wood there are required 1760J perkg per °C.</em>
The equation is:
Q = C*m*ΔT
<em>Where Q is heat in Joules,</em>
<em>C is specific heat (1760J/kg°C),</em>
<em>m is mass (2kg)</em>
<em>ΔT is change in temperature (50°C - 10°C = 40°C)</em>
Replacing:
Q = 1760J/kg°C*2kg*40°C
Q = 140800J
Right option is:
<h3>A. 140,800 J
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