All categories

2 years ago

If an element has a mass number of 222 and an atomic number of 86, how

Chemistry

1 answer:

svlad2 [7]2 years ago

5 0

Answer:

136

Explanation:

The Mass Number is the combination of the amount of Protons and Neutrons in an element, so if the total mass is 222, and the amount of protons is 86, then you can do 86 + x = 222 to find that x is equal to 136

You might be interested in

Emily wanted to see what battery lasted the longest. She put each battery into a clock and recorded the time that the clock stop

Andru [333]

Answer:

independent variable -- different batteries

dependent variable -- the time that clock stop

Explanation:

In an experiment or a research study, there are two type of variables that can affect the result of the experiment or the conclusion. They are independent variable and the dependent variable.

An independent variable may be defined as that variable in an experiment which can be changed or can be controlled in the scientific experiment in order to test the effect on the dependent variable. It cannot be changed by other variables.

On the other hand, dependent variable are those are those which can be altered or change that can affect the experiment.

In the context, Emily uses the different types of the batteries as an independent variable and the time where the clock stopped in the dependent variable in her research.

6 0

3 years ago

If a pork roast must absorb kJ to fully cook, and if only 10% of the heat produced by the barbecue is actually absorbed by the r

kolezko [41]

Answer:

1,033.56 grams of carbon dioxide was emitted into the atmosphere.

Explanation:

$C_3H_8(g)+5O_2(g)\rightarrow 3CO_2(g)+4H_2O(g),\Delta H_{rxn}=-2044 kJ/mol (assuming)$

Energy absorbed by pork,E = $1.6\times 10^3 kJ$ (assuming)

Total energy produced by barbecue = Q

Percentage of energy absorbed by pork = 10%

$10\%=\frac{E}{Q}\times 100$

$Q=\frac{E}{10}\times 100=\frac{1.6\times 10^3 kJ}{10}\times 100=1.6\times 10^4 kJ$

Since, it is a energy produced in order to indicate the direction of heat produced we will use negative sign.

Q = $-1.6\times 10^4 kJ$

Moles of propane burnt to produce Q energy =n

$n\times \Delta H_{rxn}=Q$

$n=\frac{Q}{\Delta H_{rxn}}=\frac{-1.6\times 10^4 kJ}{-2044 kJ/mol}=7.83 mol$

According to reaction , 1 mol of propane gives 3 moles of carbon dioxide. then 7.83 moles of will give:

$\frac{1}{3}\times 7.83 mol=23.49 mol$ carbon dioxide gas.

Mass of 23.49 moles of carbon dioxide gas:

23.49 mol × 44 g/mol =1,033.56 g

1,033.56 grams of carbon dioxide was emitted into the atmosphere.

8 0

2 years ago

What is the molarity of a solution which contains 0.80 mol of HCl in 250mL of<br> solution?

mariarad [96]

Answer:

3.2M HCl Solution

Explanation:

Molarity = moles of solute / volume of solution expressed in liters

moles of solute = 0.80 moles HCl

volume of solution = 250 ml = 0.250 Liter

Molarity (M) = 0.80 moles HCl / 0.250 Liters = 3.2M HCl Solution

6 0

2 years ago

What's the definition if blood

ANEK [815]

Blood is a liquid substance flowing through the arteries and veins of the body. In a healthy normal person, approximately 45% of their blood volume are cells (mostly red blood cells, white blood cells and platelets).

hope this helps!

8 0

2 years ago

The average kinetic energy of the particles in an object is directly proportional to its

Galina-37 [17]

C. Temperature the average <span> kinetic energy of the particles in an object is directly proportional to its temperature </span>

6 0

3 years ago

Read 2 more answers