If Beryllium has a mass number of 7 and atomic number of 4, how many protons does it have?

Answer:

Francis Bacon was the first to formalize the concept of a true scientific method, but he didn't do so in a vacuum. The work of Nicolaus Copernicus (1473-1543) and Galileo Galilei (1564-1642) influenced Bacon tremendously.

Answer:

Mass = 22.725 g

Explanation:

Given data:

Mass of potassium nitrate required = ?

Volume of solution = 3.00 ×10² mL

Molarity of solution = 0.750 M

Solution:

Formula:

Molarity = number of moles of solute / L of solution

Now we will convert the volume into L.

3.00 ×10² mL × 1L  /1000 mL

0.003 ×10² L or 0.3 L

now we will put the values in formula.

0.750 M  = n / 0.3 L

n = 0.750 M × 0.3 L

M = mol/L

n = 0.225 mol

Mass of potassium nitrate:

Mass = number of moles  × molar mass

Mass = 0.225 mol × 101 g/mol

Mass = 22.725 g

Answer:

42.9158 m/s

Explanation:

the answer is there above

Answer:

I think b but I could be wrong

Answer:

a

Explanation:

i just took it

Answer:Find it

Explanation:

Aluminium-27 is an isotope of aluminium characterized by the fact that is has a mass number equal to  

27

.

Now, an atom's mass number tells you the total number of protons and of neutrons that atom has in its nucleus. Since you're dealing with an isotope of aluminium, it follows that this atom must have the exact same number of protons in its nucleus.

The number of protons an atom has in its nucleus is given by the atomic number. A quick looks in the periodic table will show that aluminium has an atomic number equal to  

13

.

This means that any atom that is an isotope of aluminium will have  

13

protons in its nucleus.

Since you're dealing with a neutral atom, the number of electrons that surround the nucleus must be equal to the number of protons found in the nucleus.

Therefore, the aluminium-27 isotope will have  

13

electrons surrounding its nucleus.

Finally, use the known mass number to determine how many neutrons you have

Answer:

D.

Explanation:

Answer:

The correct answer is d. i took the test and got it right

Explanation:

Answer:

c

Explanation:

Nitrogen is in period 2, and has electrons in both 1 and 2.

The electron seeks to go up to energy level n = 2 from level 1, which is the initial energy level. Since the second energy level has more energy than the first, the electron must gain energy to travel from n = 1 to n = 2. A neutral atom of nitrogen has electrons in energy levels are 1 and 2.

Any discrete value from a set of total energy values for a subatomic particle constrained by a force to a finite space or for a system of such particles, such as an atom or a nucleus, is referred to as the energy level, also known as the energy state, in physics.

"Energy levels" refer to the areas around the nucleus where an atom's electrons are positioned. The 3-dimensional region around the nucleus where electrons are most likely to be is represented by an energy level.

Every component of the cycle of wellness depends on energy. Our attitude and physical health both get better as we get more energy. Connecting with people, exercising, and feeling driven to work hard and accomplish personal objectives are all more likely.

Thus, option C is correct.

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Answer:

See explanation

Explanation:

A chemical reaction is said to have occurred when there is a permanent, irreversible change in a substance.

Considering the fruit in the question, the changes in the fruit can not be reversed. Nothing can ever be done to return the fruit to its original form. This ultimately shows that a chemical reaction has taken place.

Secondly, the occurrence of a chemical reaction can be confirmed by evolution of a gas. The foul smell that filled the kitchen is the gas evolved during the chemical reaction involving the rotten fruit.

Answer:

conserve mass.

Explanation:

Answer:

where are the group?

Explanation:

Answer:

Transition metals

Explanation:

Answer:

don't know this but going to figure out

Answer:

liquid

Explanation:

Answer:

1. Atoms, Have different properties depending on the number of protons.

2. Mixtures, The ingredients maintain their properties when they are placed together or taken apart.

3. Compounds, The atoms take on new properties when they bond together or are separated.

Explanation:

Answer:

A gas is evolved

The ingredients can not be recovered

Explanation:

A chemical change is one in which a new substance is formed and it is not easily reversible.

One major ingredient used in cake baking is the baking powder or baking soda.

Baking a cake can be viewed as a chemical change. This is because, when the baking powder or soda is added in the presence of yeast, carbon dioxide gas is evolved as tiny bubbles of gas which makes the cake light and fluffy. Heat is equally given off in the process. The baking powder and other cake ingredients can not be recovered, hence, we can conclusively assert that a chemical change has taken place.

Answer:

Nuclear

Explanation:

Nuclear is a un-natural and newer type of energy source that can spread lethal toxins into the air causing living things to die. On top of that is it sometimes very unstable and sometimes if it's not disposed correctly it can cause high levels of radiation.

Matter cannot be created or destroyed.

Conservation of mass applies to a closed system, where the masses before and after the reaction are the same

Or

Conservation of mass means:

In a closed/isolated system, the total mass of the substance before the reaction will be equal to the total mass of the reaction product.

So what changes is the form, into a liquid, gas or solid

while what does not change is the mass

Given parameters:

Number of moles of iron = 0.251 moles

Unknown:

Number of atoms = ?

Solution:

A mole of an atom contains the Avogadro's number of particles;

   Avogadro's particles  = 6.02 x 10²³ atoms

     1 mole of atom  =  6.02 x 10²³ atoms

      0.251 moles = 0.251 x 6.02 x 10²³    = 1.51 x 10²³ atoms

The number of atoms here is  1.51 x 10²³ atoms

The number of atoms in 0.251 mol of Iron sample has been [tex]1.51\;\times\;10^2^3[/tex].

The number of atoms in a mole of sample has been given by the Avogadro law. According to the Avogadro law, the number of atoms in 1 mole of sample has been equivalent to the Avogadro number.

The Avogadro number has been a constant quantity with the value of [tex]6.023\;\times\;10^2^3[/tex].

The given mole of iron has been 0.251 mol.

The number of atoms in the sample has been given as:

[tex]\rm 1\;mol=6.023\;\times\;10^2^3\;atoms\\ 0.251\;mol=0.251\;\times\;6.023\;\times\;10^2^3\;atoms\\ 0.251\;mol=1.51\;\times\;10^2^3\;atoms[/tex]

The number of atoms in 0.251 mol of Iron sample has been [tex]1.51\;\times\;10^2^3[/tex].

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Mass of Li = 237.38 g

The mole itself is the number of particles contained in a substance amounting to 6.02.10²³  

[tex]\large {\boxed {\boxed {\bold {mol = \frac {mass} {molar \: mass}}}}[/tex]

Moles of Li = 34.2

Molar mass(MW) of Li = 6.941 g/mol

then mass of Lithium (Li) :

[tex]\tt mol=\dfrac{mass}{MW}\\\\mass=mol\times MW\\\\mass=34.2\times 6,941~g/mol\\\\mass=\boxed{\bold{237.38~g}}[/tex]

Answer:

l, ll, lll, v

Explanation:

I just took the test ;)

Answer:

₈₈Ra²²⁶  →   ₈₆Rn²²²  + ₂He⁴  + energy

Explanation:

Alpha beta and gamma radiations are the examples of ionizing radiations.

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles having  two proton and two neutrons. It is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4  and atomic number less than 2 as compared to parent atom.

For example:

₈₈Ra²²⁶  →   ₈₆Rn²²²  + ₂He⁴  + energy

Properties of alpha radiation:

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

Another example:

₉₂U²³⁸   →   ₉₀Th²³⁴  + ₂He⁴  + energy

Another process that contributes to the formation of rock at point R is the:

According to the given question, we need to find another process which can help with the rock formation at point R where the rock melts underground to form magma.

As a result of this, another process through which makes a significant contribution to the formation of rock at point R is the cooling of the lava as the magma which has been melted runs down the mountain.

Therefore, the correct answer is option B

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Answer:

An electron in the first shell has more energy than an electron in the second shell.

Explanation:

The number of protons, neutrons, and electrons is iodine-132, Iodine has 53 protons and 53 electrons as it has no charge the number of protons equals the number of electrons. Iodine-131 has 131 protons as well as neutrons.

Protons are subatomic particles that have a positive charge. The strong nuclear force holds protons together in the nucleus of an atom. Neutrons are non-charged subatomic particles (they are neutral).

A proton is a subatomic particle found in every atom's nucleus. The particle has a positive electrical charge that is equal to and opposite to the electron's.

Iodine-132 is the number of protons, neutrons, and electrons. Iodine has 53 protons and 53 electrons because it has no charge, so the number of protons equals the number of electrons. Iodine-131 contains 131 protons and neutrons.

Thus, there will be 131 protons as well as neutrons in iodine-131.

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The % lithium by mass in a sample of pure lithium carbonate : 18.79%

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

% Lithium (Li) in Li₂CO₃(lithium carbonate) will remain the same even if the mass amount of Li₂CO₃ changes

Ar of Li = 6.941 g/mol

MW of  Li₂CO₃  = 73.891 g/mol

[tex]\tt \%Li=\dfrac{2.Ar~Li}{MW~Li_2CO_3}\times 100\%\\\\\5Li=\dfrac{2\times 6.941}{73.891} \times 100\%=18.79\%[/tex]

Answer:

4.05/28=0.144g/ml

Explanation:

Answer:

Explanation:

theory

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When water combines with carbon dioxide in the atmosphere, it will form carbonic acid, which is a weak acid. If this weak acid comes in contact with a rock, it will cause some of the rock to be dissolved. This process can also be referred to as weathering.