Answer:
Na (sodium)
Explanation:
An atom, which is the smallest indivisible particle of an element, contains three sub-atomic particles namely: proton, electron, and neutron. An atom is said to be neutrally charged if it contains a charge 0.
In a neutral atom, the number of electrons and the number of protons in an element are equal. These numbers are called the ATOMIC NUMBER. That is, in a neutral atom;
proton no. = electron no. = Atomic no.
Hence, in this case where Silicon atom has an electron number of 14. If three of this electrons are removed, there will be 11 electrons left, hence, this atom becomes SODIUM element, which has 11 electrons in its atom, with chemical symbol Na.
26. A pathogen is any organism that causes a disease. Which of the following is an example of a pathogen that
infects humans?
A.parasite
B.plasmid
C.plant cell
D.plasma membrane
Answer:
A.parasite
Explanation:
I’ve missed this question twice now. Please help
Answer:
then it only gotta be 2 other options .
Explanation:
Inspiration for new types of synthetic materials often comes from observations of…
Answer and Explanation:
Inspiration for new types of synthetic materials come from natural materials where a derivative is needed to be used in situations where properties of a natural material are adjusted. Inspirations for new types of synthetic materials can also come from current synthetic materials that create toxins, and new ones are created with the same properties but with less harmful downsides.
The strongest spring tide occurs when?
Answer:
the sun and moon are aligned with the earth.
Answer:
uhhh first or third quarter
Explanation:
how does the structure of each passage help determine the content of the passage?
a. Passage I contains a character study, but Passage 2 focuses more on concepts.
b. Passage 2 contains significant cultural information, but Passage 1 illustrates history.
c. Passage 1 explains a scientific phenomenon,
but Passage 2 is purely fictional.
d. Passage 2 describes ongoing action, but
Passage 1 focuses more on feelings.
The answer to the question is a. Passage I contains a character study, but Passage 2 focuses more on concepts.
for all who were wondering
How many molecules are in 38.4 moles of NF3?
Answer:3
Explanation:
I added and substituted for the garlic
If your grandparents started an account that does not gain interest for you when you were ten with $100 in it. Then when you were fifteen it had $1925. When you were twenty it had $3,750. Demonstrate how much your grandparents are putting in the account
Answer:
each year they are adding £31.25 to the bank account as £31.25 =£375 and times by 5 is £1875 but i did not include the $100 at the beginning
Explanation:
How many moles are in 6.3 x 10^22 molecules of H3PO4?
0.10 mol H₃PO₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
6.3 × 10²² molecules H₃PO₄
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
Set up: [tex]\displaystyle 6.3 \cdot 10^{22} \ molecules \ H_3PO_4(\frac{1 \ mol \ H_3PO_4}{6.022 \cdot 10^{23} \ molecules \ H_3PO_4})[/tex]Multiply: [tex]\displaystyle 0.104616 \ moles \ H_3PO_4[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
0.104616 mol H₃PO₄ ≈ 0.10 mol H₃PO₄
A sample of lead (Pb) has a volume of 5 cm3 and a mass of 56.5 g. What is
the density of lead?
Hey there!
The formula for density is d = m/v.
The mass of the sample is 56.5 g, and the volume of the sample is 5 cm³.
So, to plug these values into the equation, we have:
[tex]d=\frac{56.5}{5}[/tex]
Simplified, this is:
d = 11.3
The unit for this is g/cm³, or grams per cubic centimeter.
So, the density of lead is 11.3 g/cm³.
Hope this helps!
Answer:
11.3 g/cm³
Explanation:
Density of lead
= Mass / Volume
= (56.5 g) / (5 cm³)
= 11.3 g/cm³
What is conclusive evidence that mixing sugar in water is a physical change
Explanation:
1) their is no formation of new substance
2) the reaction can be reverse i.e if we heat sugar solution it we give us sugar and water.
A conductor allows heat to flow easily while an insulator
Answer:
an insulator is a substance that does not readily allow the passage of heat or sound.
Explanation:
I need help as fast as possible
an ionic bond forms between a ______ and a _____
Please help me thanks so much....I’ll mark you?!?!:)))) ( 15 points)
Answer:
all of the above
Explanation:
Touching a hot stove or the melting of ice in your hand (as you squeeze it) is an example of
Answer: conduction
Explanation:
the heat passes out of the stove and into your hand. So is holding an ice cube – the heat is conducted out of your hand, and into the ice cube (that’s why your hand feels cold).
Answer:
Conduction
Explanation:
Conduction occurs when objects touch. The heat from the warmer object is transferred to the cooler object, eventually evening out the temperatures.
Draw the Lewis structure for the polyatomic nitrate anion. Be sure to include all resonance structures that satisfy the octet rule.
Answer:
See explanation and image attached
Explanation:
A poly atomic ion refers to an ion that has more than one atom. The nitrate ion is one of such! It contains three oxygen atoms and one nitrogen atom.
It is an ion in which there is charge separation as shown in the image attached to this answer. The structures shown are the Lewis structure of the nitrate ion that satisfy the octet rule.
Which of the following is an expression of Boyle's law?
A. PT= constant
B. P/T=constant
C. V/T=constant
D. PV=constant
The expression of Boyle's law is to be considered as the PV=constant.
Hence, the option d is correct.
What is Boyle's law?
In physics, the volume of the gas at a similar kind of temperature should changed oppositely along with the pressure that should be exterted on it.
Also, the expression be like
P1V1 = P2V2
hence, The expression of Boyle's law is to be considered as the PV=constant.
Hence, the option d is correct.
learn more about law here: https://brainly.com/question/14696622
Decide which element probably forms a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and oxygen.
The question is incomplete, the complete question is shown in the image attached to this answer
Answer:
Most similar - sulphur
least similar- gallium
Explanation:
The compound formed when hydrogen reacts with oxygen is water. The chemical formula of water is H2O.
Water is very similar to H2S which is the compound formed when hydrogen reacts with sulphur. The bonds in water and H2S are both polar covalent bonds.
However, gallium is a metal and its hydride (GaH3) is least similar to water.
which of the following pairs of elements is most likely to form an ionic bond
a( phosphorus and bromine
b(calcium and bromine
c( carbon and chlorine
d(silicon and oxygen
Answer:
it is calcium and bromine
Explanation:
this is because they are both ionic compounds
Over long periods of time, a series of processes continuously change rocks from one type into another. This is called the rock cycle. A combination of subsurface and surface processes are responsible for the recycling of rocks in the geosphere.(that was the story)
What two processes are responsible for changing metamorphic and igneous rock into sedimentary rock?(this is the question)
A) intrusive and extrusive
B) weathering and erosion
C) subduction and sea floor spreading
D) heat and pressure
Answer:
B) weathering and erosion
Explanation:
The two processes responsible for changing metamorphic and igneous rocks into sedimentary rocks is weathering and erosion.
Weathering is the defined as the physical disintegration and chemical decomposition of rocks to form sediments and soils.
Erosion is the removal of weathered materials from the surface of the earth.
The process of erosion and weathering serves to convert igneous and metamorphic rocks into sediments by which a sedimentary rock is formed.
Answer: The rock cycle
Explanation: Well its kinda obious that it is the rock cycle because the question says it changes countinuously to other rocks so yeah rock cycle is answer to question.
40. What is the mass of 3 moles of H 2 O
Answer:
54g
Explanation:
Given parameters:
Number of moles of H₂O = 3 moles
Unknown:
mass of water = ?
Solution:
To solve this problem, we use the expression below:
mass = number of moles x molar mass
Molar mass of H₂O = 2(1) + 16 = 18g/mol
Mass of water = 3 x 18 = 54g
PLEASE HELP! Due in 1 minute chemistry lewis structure.
Am i correct?
Suppose a psychrometer reads 80°F for the dry bulb and 76°F for the wet bulb. What is the relative humidity?
Answer: 84%
Explanation:
Using the table attached, one can find out the Relative humidity.
Look at the intersection between the temperature on the dry bulb and the difference between the temperature on the dry and wet bulb.
Dry bulb temperature = 80°F
Wet bulb temperature = 76°F
Difference = 80 - 76 = 4°F
Relative humidity is therefore:
= 84%
The half-life of sodium-24 is 15 days. A laboratory technician measures out a 72 g sample. Approximately how many grams of sodium-24 would remain after 45 days?
Answer:
after 45 days 9 g left
Explanation:
Given data:
Half life Na-24 = 15 days
Mass of sample = 72 g
Mass remain after 45 days = ?
Solution:
Number of half lives passed:
Number of half lives = time elapsed / half life
Number of half lives = 45 days / 15 days
Number of half lives = 3
At time zero total amount = 72 g
After first half life = 72 g/ 2= 36 g
At 2nd half life = 36 g/2 = 18 g
At 3rd half life = 18 g/2 = 9 g
Thus after 45 days 9 g left.
soil is formed from
A. ancestors
B. offspring
C. Parent material
D. recipe
A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound yields 1.24 g of CO2 and 0.255 g of H2O. What is the empirical formula of the compound
Answer:
C4H4O
Explanation:
1.24 g x 1mol/(44)g = 0.03mol C;
Mass of C: 0.03mol x 12.g/1mol
= 0.36g of C
mol of H: 0.255g x 1mol /(18) x2= 0.028mol
Mass of H; = 0.028g × 1 of H
Mass of O: 0.519 g – (0.36g +0.028g)= 0.131g;
0.131g/16 =0.008 mol
Divide by the smallest number of moles;
0.028/0.008 mol = 3.5; 0.03/0.008 mol =3.75, 0.008 mol/0.008 mol =1
C4H4O
Nitrogen-13 has a half-life of about 10 minutes. How much of a 320g sample of N-13 would remain after 40 minutes?
Answer:
The half-life of a radioisotope describes the amount of time it takes for said isotope to decay to one-half the original amount present in the sample.
Nitrogen-13, because it has a half-life of ten minutes, will experience two half-lives over the course of the twenty minute period. This means that 25% of the isotope will remain after this.
0.25 x 128mg = 32mg
32mg of Nitrogen-13 will remain after 20 minutes.
how many grams og gas must be relased from a 45.2 L sample of N2 at STP to reduce the volume to 45.0 L at stop
Answer:54,6
Explanation:
Answer:
yes it is 54,6
Explanation:
54,6 you ar correct you did a graet job
Which of the following is not a natural change to the envlronment? drought , flood, disease ranching
Answer:
Disease ranching
Explanation:
Floods and Droughts are caused by the enviorment. Diseases are but a product and don't affect the enviorment.
Answer:
disease ranching is not a natural change to the environment .
Explanation:
This all happen because of human activities
An empty Erlenmeyer flask weights 241.3 g. When filled with water (d = 1.00 g cmଷ ⁄ ), the flask and its contents weight 489.1 g. What is the flask’s volume? What is the mass of the flask when filled with chloroform (d = 1.48 g cmଷ ⁄ )?
Answer:
608 g
Explanation:
Mass of flask + contents = 489.1 g
Mass of flask = 241.3 g.
Mass of water = 489.1 - 241.3 = 247.8 g
Density of water = 1.0 g/cm^3
volume of water = 247.8 g/1.0 g/cm^3
Volume = 247.8 cm^3
But
Volume of flask = volume of water
Volume of flask = 247.8 cm^3
volume of chloroform = volume of flask
mass of chloroform = 1.48 g/cm^3× 247.8 cm^3
Mass of flask + chloroform = 366.7 g + 241.3 = 608 g