There is about 30 g of Californium-252 left, how much time has elapsed?

Answer:

This question appear incomplete

Explanation:

This question appear incomplete. However, let's answer the resulting questions. Firstly, let's define mass number since each of the "problems" refers to mass number. Mass number is the total number of protons and neutrons in the nucleus of an atom. It should also be noted that number of protons in any given neutral atom is the same with the number of electrons of such an atom.

1) Make a He atom with a mass of 4. How many protons did you put in the nucleus?

Answer: Helium (He) atom (having a mass number of 4) has an atomic number of 2. Atomic number is the number of protons and thus 2 protons would be in the nucleus of the Helium atom.

2) Make a Li atom with a mass number of 7. How many electrons did you place in the outermost orbital  (ring)?

Answer: Lithium (Li) atom (having a mass number of 7) has an atomic number of 3. Remember that atomic number (number of protons) equals number of electrons in a neutral atom. Thus, lithium atom would have 3 electrons; 2 electrons in it's first shell and 1 electron in it's outermost shell

3) Make a N atom with a mass number of 14. How many neutrons are in the nucleus?

Answer: Nitrogen (N) atom (with a mass number of 14) has an atomic number of 7. Since atomic number is the number of protons and mass number is the number of protons + neutrons. Then, number of neutrons would equal mass number minus atomic number:

number of neutrons = 14 - 7

number of neutrons = 7 neutrons

4) Make a B atom with a mass number of 11. How many electrons did you put in the second orbital (ring)?

Answer: An atom (Boron) with mass number of 11 has an atomic number of 5. Since atomic number eventually equals number of electrons, then Boron has 5 electrons; 2 electrons in it's first shell and 3 electrons in it's second orbital/ring.

Answer:

2 protons in the He nucleus,

1 electron in the outermost,

7 neutrons in the nucleus

3 electrons in the  2nd orbital ring

Explanation:

I just did it on E2020

Explanation:

When Sulphuric acid is slowly poured into water in a beaker the beaker becomes hot and this is exothermic reaction

when ammonium chloride is dissolved in water in a beaker the beaker becomes cold and this is endothermic reaction

An example of an exothermic reaction is rusting or iron, nuclear fission. Examples of endothermic reactions are the melting of liquid and the evaporation of water.

A chemical reaction is a process in which one or two substances or compounds, called reactants, react or get mixed with each other and form a totally new compound called a product.

Exothermic reactions are those in which energy is released into the environment after the reaction. The reactant has more energy than the products.

Endothermic reactions are those in which energy is absorbed from the environment. The product has more energy than the reactants.

Thus, rusting on iron or nuclear fission are two examples of exothermic reactions. Liquid melting and water evaporation are two instances of endothermic processes.

To learn more about a chemical reaction, refer to the below link:

https://brainly.com/question/10373907

#SPJ2

Answer:b

Explanation:

Answer:

Ba,Sr,Ca,Be

Explanation:

as atomic size increases ionisation potential decreases

Answer:

Explanation:

Deforestation has an adverse affect on air by reducing the amount of oxygen and increasing the amount of carbon dioxide as well as contributing to global warming.

Answer:

True

Explanation:

Solid molecules don't move.

Molecule of a solid are tightly packed there is no space between them so there is no movement of the molecule.

The particles (atoms or molecules) are attracted to each other. The particles (atoms or molecules) vibrate but do not move past one another. The solid retains its shape.

true

Answer:

Due to protons and electrons number.

Explanation:

The atomic particles determine the name of an atom or ion by number of protons because the number of protons determines the atomic number of an element and this atomic number distinguishes one element from another and number of electrons also be different in atoms of the same element due to chemical bonding, due to which ions are produced. So we can say that atomic particles such as proton, electron and neutrons determine the name of an atom or ion.

Answer:

Photosynthesis reactions are naturally occurring processes that take place in all green plants and most algae. During this process the plant uses light energy, carbon dioxide, and water to make food and then releases oxygen which all living organisms require to the atmosphere.During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. These sugar molecules are the basis for more complex molecules made by the photosynthetic cell, such as glucose

Explanation:

Answer:

CaO, CaF2, or CaCl2

Explanation:

In an ionic compound, the charges need to balance out. This is the only set of compounds that fits this criteria.

Answer:

CaO CaF2 CaCl2 are ionic

Explanation:

Because electronegativity difference between calcium and other atom is more than 1.7

Answer:

4^4, or 256

Explanation:

When dividing numbers with exponents and the same base, you will subtract from the exponents and keep the base the same.

Answer:

may involve a change in total mass

involve very high-energy changes

involve changes in nuclides when decay occurs

Explanation:

A nuclear reaction is different from a typical chemical reaction. The reaction occurs within the nucleus and involved nuclear materials.

We can see here that the number of lone pairs surround the boron atom is A. 0.

A boron atom is an atom of the chemical element boron, which is represented by the symbol B in the periodic table. Boron is a metalloid with atomic number 5, meaning it has five protons in its nucleus. It belongs to Group 13 (formerly known as Group IIIA) of the periodic table and is located in period 2.

The Lewis structure of [tex]BF_{3}[/tex] indicates that boron (B) forms three single bonds with three fluorine (F) atoms. Each bond consists of a pair of electrons shared between boron and fluorine. Since there are no unshared electron pairs around the boron atom, the answer is option a. 0.

Learn more about boron atom on https://brainly.com/question/864236

#SPJ6

Answer: A property closely related to an atom's mass number is its atomic mass. The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.

Hope this helps....... Stay safe and have a Merry Christmas!!!!!!!! :D

The oxidation number for S in the compound SO₃ : +6

The formula for determining Oxidation Numbers :

1. Single element atomic oxidation number = 0.

Group IA (Li, Na, K, Rb, Cs, and Fr): +1

Group IIA (Be, Mg, Ca, Sr and Ba): +2

H in compound = +1, except metal hydride compounds (Hydrogen which binds to groups IA or IIA) oxidation number H = -1, for example, LiH, MgH₂, etc.

2. Oxidation number O in compound = -2, except OF₂ = + 2 and in peroxide (Na₂O₂, BaO₂) = -1 and superoxide, for example KO₂ = -1/2.

3 The oxidation number in an uncharged compound = 0,

Total oxidation number in ion = ion charge, Example NO₃⁻ = -1

The oxidation number for S in SO₃ :

[tex]\tt oxidation~number~of~S+3\times oxidation~number~of~O=0\\\\oxidaton~number~of~S+3\times(-2)=0\\\\oxidation~number~of~S=+6[/tex]

Answer:

3900 mol Pb

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

8.1 × 10⁵ g Pb

Step 2: Identify Conversions

Molar Mass of Pb - 207.2 g/mol

Step 3: Convert

[tex]8.1 \cdot 10^5 \ g \ Pb(\frac{1 \ mol \ Pb}{207.2 \ g \ Pb} )[/tex] = 3909.27 mol Pb

Step 4: Check

We are given 2 sig figs. Follow sig fig rules and round.

3909.27 mol Pb ≈ 3900 mol Pb

Answer:

No

Explanation:

My sister uses this all the time and it is perfectly safe

Answer:

no

Explanation:

as long as you change it up a little and word it to look like your own

The value of x = 97

The unknown angles : 97°,97°, 107° and 59°

One variable linear equation is an equation that has a variable and the exponent number is one.  

Can be stated in the form:  

[tex]\large{\boxed{\bold{ax=b}}[/tex]

or  

ax + b = c, where a, b, and c are constants, x is a variable  

The parallelogram has total angle of 360°.

The value of each of the 4 angles of the parallelogram :

1. x°

2. x°

3. x+10°

4. 59°

The sum of the four angles of this parallelogram is :

[tex]\tt x+x+x+10+59=360[/tex]

So that the mathematical equation becomes (by combining the like terms) :

[tex]\tt 3x+69=360\\\\3x=291\\\\x=97[/tex]

So the value of the four angles (by entering the x value)

1. 97°

2. 97°

3. x+10=97+10=107°

4. 59°

Answer:

For your first question, Curium does not occur naturally on Earth, meaning that it is not produced naturally on Earth. However, it can be formed in nuclear reactors.

For your second question, Curium has been used to provide power to electrical equipment used on space missions, but doesn't seem to be that important overall.

Explanation:

Hope this helped!

Answer:

6.02 x 10²³ atoms

Explanation:

Given parameters:

Number of moles CaSO₄ = 1 mole

Unknown:

Number of Ca atoms in the given compound = ?

Solution:

The given compound is:

          CaSO₄

     1 mole of CaSO₄  is made up of 1 mole of Ca atoms

Now;

   1 mole of any substance contains 6.02 x 10²³ atoms

  1 mole of Ca atoms will also contain 6.02 x 10²³ atoms

Answer:

second box is 2 C, third box is 3 C, and the last box is 3 C.

Explanation:

Answer:

417

Explanation:

50um is

50000nm

50000:120=417

Answer: mark as Brainliest

10 moles

Explanation:

moles=mass/molar mass, therefore 403.1/(24.31+16)=10

Answer:

10 moles

Explanation:

moles=mass/molar mass, therefore 403.1/(24.31+16)=10

Answer:

limiting reactant

Answer: B) limiting reagent

Answer:

C. Electrons flow from an outlet into a toaster, causing it to heat a

slice of bread.

Explanation:

Current produces a heating effect. Current may be used to produce a heating effect in appliances such as the electric pressing iron, toaster, oven etc.

When electrons flow from an outlet into a toaster and the current thus obtained heats a slice of bread, current is said to flow from the outlet into the toaster.

Let us remember that current refers to the flow of electrons in a circuit.

Answer: The empirical formula is [tex]CH_2[/tex] and molecular formula is [tex]C_4H_8[/tex]

Explanation:

We are given:

Mass of [tex]CO_2[/tex] = 18.95 g

Mass of [tex]H_2O[/tex]= 7.759 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 18.59 g of carbon dioxide, =[tex]\frac{12}{44}\times 18.59=5.07g[/tex] of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 7.759 g of water, =[tex]\frac{2}{18}\times 7.759=0.862g[/tex] of hydrogen will be contained.

Mass of C = 5.07 g

Mass of H = 0.862 g

Step 1 : convert given masses into moles.

Moles of C =[tex] \frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{5.07g}{12g/mole}=0.422moles[/tex]

Moles of H=[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.862g}{1g/mole}=0.862moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C =[tex]\frac{0.422}{0.422}=1[/tex]

For H =[tex]\frac{0.862}{0.422}=2[/tex]

The ratio of C : H = 1: 2

Hence the empirical formula is [tex]CH_2[/tex].

The empirical weight of [tex]CH_2[/tex] = 1(12)+2(1)= 14 g.

The molecular weight = 56.1 g/mole

Now we have to calculate the molecular formula.

[tex]n=\frac{\text{Molecular weight }}{\text{Equivalent weight}}=\frac{56.1}{14}=4[/tex]

The molecular formula will be=[tex]4\times CH_2=C_4H_8[/tex]

Answer:

Number of moles of HCl = 0.17 mol

Explanation:

Given data:

Volume of solution = 347 mL

Molarity of solution = 0.48 M

Number of moles of HCl present = ?

Solution:

Formula:

Molarity = number of moles of HCl / volume in L

Volume in L:

347 mL× 1L / 1000 mL

0.347 L

by putting values in formula:

0.48 mol/L = number of moles / 0.347 L

Number of moles = 0.48 mol/L × 0.347 L

Number of moles = 0.17 mol

sorry I didn't understand the question ask you to do

Answer:

V₂ =  116126.75 cm³

Explanation:

Given data:

Radius of balloon = 15 cm

Initial pressure = 2 atm

Initial temperature = 35 °C (35 +273 = 308K)

Final temperature = -20°C (-20+273 = 253 K)

Final pressure = 0.3 atm

Final volume = ?

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

Initial volume of balloon:

V = 4/3πr³

V = 4/3×22/7×(15cm)³

V = 14137.17 cm³

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 2 atm × 14137.17 cm³ × 253 K / 308 K × 0.3 atm

V₂ = 7153408.02 atm .cm³. K / 61.6 K.atm

V₂ =  116126.75 cm³

Answer:

18.2g/mol is the molar mass of the unknown solid assuming change in freezing point is 2.5°C

Explanation:

In this problem, there is no value of the freezing point depression and the constant for benzene, if:

Freezing point decreases by 2.5°C

And freezing point depression constant for benzene is 5.12°C/m

We can solve the problem as follows:

The freezing point depression is a colligative property that follows the equation:

ΔT = kf*m*ï

Where ΔT is change in temperature (We are assuming is 2.5°C)

Kf is freezing point depression constant for benzene (5.12°C/m)

m is molality of solution (Moles solute / kg solvent)

i is Van't hoff factor (For all solutes dissolved in organic solvents = 1)

Solving for m:

2.5°C = 5.12°C/m*m*1

m = 0.4883m

As molality is defined as moles of solute / kg of solvent and kg of solvent are 0.3632kg:

0.4883m = moles solute / 0.3632kg

0.177 moles of solute

Molar mass is defined as the mass of one mole of substance. Thus, molar mass of an unknown solid is:

3.232g / 0.177 moles of solute =