Measurements may be accurate, meaning that the measured value is the same as the true value; they may be precise, meaning that multiple measurements give nearly identical values (i.e., reproducible results); they may be both accurate and precise; or they may be neither accurate nor precise. The goal of scientists is to obtain measured values that are both accurate and precise.
Suppose, for example, that the mass of a sample of gold was measured on one balance and found to be 1.896 g. On a different balance, the same sample was found to have a mass of 1.125 g. Which was correct? Careful and repeated measurements, including measurements on a calibrated third balance, showed the sample to have a mass of 1.895 g. The masses obtained from the three balances are in the following table:
Answer:
4Na + O₂ → 2Na₂O
6.82g
Explanation:
The combustion of sodium involves combining the element with oxygen gas:
4Na + O₂ → 2Na₂O
We have been given 5g of Na.
The balanced reaction equation is given as shown above. This reaction is also a synthesis or combination reaction.
b. Maximum amount of product that can be obtained.
Sodium is the limiting reactant and it will determine the amount of product that can be formed.
To solve this, we find the number of moles of the given sodium.
Mass of given sodium = 5g
Molar mass of Na = 23g/mol
Number of moles of Na =
Insert the parameters and solve;
Number of moles of Na = = 0.217moles
From the balanced reaction equation:
4 moles of Na will produce 2 moles of Na₂O
0.217 moles of Na will produce = 0.11mole of Na₂O
So;
Mass of Na₂O = number of moles x molar mass
Molar mass of Na₂O = 2(23) + 16 = 62g/mol
Mass of Na₂O = 0.11 x 62 = 6.82g
Answer:
The second option
Explanation:
The process of elimiation.
1. We know liquids dont have a definite shape, they will morph into whatever enviroment theyre in
3. Solids dont expand based on what container theyre in, they either dont fit or they do
4. We know that liquid expands, so we can also rule this one out.
Which leaves us with option 2 to be correct.
Answer:
The answer to your question is: Volume = 1.074 x 10⁻⁶ m³
Explanation:
Data
Salt crystal measures 5.44 x 10⁻² m ; 2.5 x 10⁻³ m; 7.9 x 10⁻³ m
From the information I suppose it is a cube, then,
Volume of a cube = length x width x height
Volume = 5.44 x 10⁻² m x 2.5 x 10⁻³ m x 7.9 x 10⁻³ m
Volume = 0.000001074 m³
Volume = 1.074 x 10⁻⁶ m³
phosphorus in water is rapid combustion.