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4 years ago

Q05 the "atomic number" of an atom is determined by the number of ________ it has.

1 answer:

6 0

The atomic number of an atom is determined by the number of protons it has..

It is also the whole number shown on the periodic table

You might be interested in

Which formula represents Carbonic acid

Degger [83]

Answer:

H2CO3 represents carbonic acid

8 0

3 years ago

A chemist wishing to do an experiment requiring 47Ca2+(half-life = 4.536 days) needs 5.00 g of the nuclide. What mass of 47CaCO

Artyom0805 [142]

Answer: The answer is 6.78 grams.

Explanation: The equation used for solving this type of problems is:

$\frac{N}{N_0}=(\frac{1}{2})^n$

where, $N_0$ is the initial amount of radioactive substance, N is the remaining amount and n is the number of half lives.

Number of half lives is calculated on dividing the given time by the half life.

n = time/half life

Time is given as 48.0 hours and the half life is given as 4.536 days. let's make the units same and for this let's convert the half life from days to hours.

$4.536days(\frac{24hours}{1day})$

= 108.864 hours

So, $n=\frac{48.0}{108.864}$ = 0.441

Since 5.00 g is the required amount when the radioactive substance is delivered to the scientist, it would be the final amount that is N. We need to calculate the initial amount. Let's plug in the values in the equation:

$\frac{5.00}{N_0}=(\frac{1}{2})^0^.^4^4^1$

$\frac{5.00g}{N_0}=0.737$

$N_0=\frac{5.00g}{0.737}$

$N_0$ = 6.78 g

So, 6.78 g of the radioactive substance needs to be ordered.

4 0

4 years ago

The reaction represented by this graph is an exothermic reaction. According to the graph, which statement is true? Reactants hav

Sunny_sXe [5.5K]

Answer:

Reactants have more energy than products

Explanation:

Generally, in an exothermic reaction heat is released. In other words, energy is released. So you start with reactants which have a set amount of stored chemical energy, and you lose some in the reaction. Since energy is 'leaving', the stored chemical energy in the products is less than what we started with in the reactants. When given a graph, you can tell this is true because going from left to right, the line representing the stored chemical energy will start at a higher level than where it ends.

7 0

3 years ago

Read 2 more answers

while the substance is a liquid at what temperature do the molecules of the substance have the greatest average kinetic energy

dalvyx [7]

The molecules of the liquid will be having the greatest average kinetic energy when the temperature of the liquid reaches its boiling point.

<u> Explanation: </u>

Average kinetic energy is the measure of kinetic energy exhibited by the molecules of any substance. It is directly proportionate to the temperature of the substance. According to kinetic molecular theory,

$k=\frac{3 R T}{2 N_{A}}$

As the molecules in solids are mostly closely packed, so they will attain the least kinetic energy of molecules in solid phase. Similarly, the molecules in liquid are slightly loosely packed and on increasing the temperature, the molecules will attain more energy to increase their neighbouring distances.

And when that temperature reaches the boiling point of that liquid substance, the molecules had attained the maximum amount of energy to increase its average kinetic energy to the maximum limit and transferring the liquid molecules to gaseous state.

As the molecules in gas phase are very loosely packed. The starting of the change in the state of molecules from liquid to gas phase on reaching the boiling point indicate the maximum average kinetic energy at that point.

4 0

4 years ago

How is energy involved in what happens during a chemical reaction

Semmy [17]

When the reactants have higher chemical change.

7 0

3 years ago