i need help ):
soo.. help me ! please (:
Answer:
23 Sandwiches
6 slices of bread
0 slices of cheese
Explanation:
brainliest pls:)
What causes your skin to feel warm when it is in the sun on a summer day?
A Particles in the atmosphere reflect energy from the Sun downward.
B Hot particles from the Sun still carry some heat when they reach your skin.
C The solar wind carries heated air from the Sun's atmosphere to Earth's surface.
D The Sun radiates energy that passes through space and the atmosphere to your skin.
Answer:
idek akxkkwskkd nwkdkekekd
Determine the volume (mL) of 15.0 M sulfuric acid needed to react with 45.0 g of
aluminum to produce aluminum sulfate.
Answer:
167 mL.
Explanation:
We'll begin by calculating the number of moles in 45 g of aluminum (Al). This can be obtained as follow:
Mass of Al = 45 g
Molar mass of Al = 27 g/mol
Mole of Al =?
Mole = mass /Molar mass
Mole of Al = 45/27
Mole of Al = 1.67 moles
Next, the balanced equation for the reaction. This is given below:
2Al + 3H2SO4 → Al2(SO4)3 + 3H2
From the balanced equation above,
2 moles of Al reacted with 3 moles of H2SO4.
Next, we shall determine the number of mole of H2SO4 needed to react with 45 g (i.e 1.67 moles) of Al. This can be obtained as:
From the balanced equation above,
2 moles of Al reacted with 3 moles of H2SO4.
Therefore, 1.67 moles of Al will react with = (1.67 × 3)/2 = 2.505 moles of H2SO4.
Thus 2.505 moles of H2SO4 is needed for the reaction.
Next, we shall determine the volume of H2SO4 needed for the reaction. This can be obtained as follow:
Molarity of H2SO4 = 15.0 M
Mole of H2SO4 = 2.505 moles
Volume =?
Molarity = mole /Volume
15 = 2.505 / volume
Cross multiply
15 × volume = 2.505
Divide both side by 15
Volume = 2.505/15
Volume = 0.167 L
Finally, we shall convert 0.167 L to mL. This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.167 L = 0.167 L × 1000 mL / 1 L
0.167 L = 167 mL
Thus, 0.167 L is equivalent to 167 mL.
Therefore, 167 mL H2SO4 is needed for the reaction.
J.J. Thomson's plum pudding model of the atom followed the discovery of
A)
negatively charged particles with a very small mass.
B)
positively charged particles with a very large mass.
0)
negative electrons that revolved around a positive nucleus.
D)
positively charged protons that were contained in a concentrated area.
J.J. Thomson's plum pudding model of the atom followed the discovery of negatively charged particles with a very small mass. Thus, the correct option for this question is A.
Who was J. J. Thomson?J.J. Thomson was a British physicist who discovered sub-atomic particles known as electrons within an atom. He also announced that atoms are made up of smaller components.
The plum pudding model is defined by Thomson in order to demonstrate that negatively charged sub-atomic particles known as electrons are surrounded by a volume of positively charged particles known as protons. It is one of the historical scientific model of the atom that governs all sorts of properties of sub-atomic particles.
Therefore, "negatively charged particles with a very small mass" is the discovery that follows J.J. Thomson's plum pudding model of the atom. Thus, the correct option for this question is A.
To learn more about the Plum pudding model, refer to the link:
https://brainly.com/question/4839193
#SPJ2
3. What is the pairing arrangement of the nitrogenous bases? _____________ pairs with __________ and ____________ pairs with ___________.
Answer:
Adenine pairs with thymine and guanine pairs with cytosine
trioxocarbonate iv acid
Answer:
Trioxocarbonate (iv) are salts derived from trioxocarbonate (iv) acid when it reacts with metals and metallic oxides. All trioxocarbonate (iv) salts of Sodium (Na), Potassium (K) and Ammonium(NH4+) are soluble while all others are insoluble.
A sample is found to contain 2.98x10^-10 g of salt. Express this quantity in nanograms.
This quantity = 0.298 nanograms(ng)
Further explanationMass is one of the principal quantities, which is related to the matter in the object
The main mass unit consists of 7 units of other than other units of mass such as quintals, tons, pounds, ounces:
Kilogram, kg
Hectogram, hg
Decagram, dag
gram, g
Desigram, with
centigram, cg
milligram, mg
Each unit descends then multiplied by 10, and if one unit increases then divided by 10
Conversion of other mass units:
10⁻³ g ⇒mg-milligrams
10³ g ⇒kg-kilograms
10⁻⁶ g ⇒µg-micrograms (mcg)
10⁶ g ⇒Mg-megagrams (tons)
10⁻⁹ g ⇒ng-nanograms
10⁹ g ⇒Gg-gigagram
10⁻¹² g ⇒pg-pikogram
2.98 x 10⁻¹⁰ g to nanograms(ng)
[tex]\tt 2.98\times 10^{-10}\times 10^9=0.298~ng[/tex]
The density of a substance is 1.63 grams per milliliter. What is the volume, in ml, of a sample of the substance with a mass of 5.40Kg? 1000 g = 1 kg
Answer:
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Explanation:
Naming inconic compounds and lots of iconic naming
if you just look up the answer it comes up btw!!
have a great day
An overhead view of two people at the start of a maze. The person in a purple shirt has a line running forward, right, backward, right, forward, ending with an arrowhead pointing to a large gold star. The person in a green shirt has a line running forward, right, backward, right, forward, right, backward, right, forward, ending with an arrowhead pointing to a small gold star.
Zamir and Talia raced through a maze. Zamir walked 2 m north, 2 m east, 4 m south, 2 m east, 4 m north, 2 m east, 3 m south, 4 m east, and 4 m north. Talia walked 2 m north, 6 m east, 3 m south, 4 m east, and 4 m north.
Compare their distances:
Zamir walked
meters and Talia walked
Answer:
Zamir walked
27
meters and Talia walked
19
meters.
Explanation:
27 and 19
Answer:
zamir:27 Talia:19
Explanation:
i got it right on my test :)
Which describes a speed?
O A. Moving 8 meters in 2 seconds
O B. Falling down at 100 miles/hr
O C. Moving north at 40 km/hr
O D. Speed changing from 2 km/hr to 5 km/hr
11) Nitrogen oxides undergo many interesting reactions in the environment and in industry. Given the following information, calculate H for the overall equation:
2 NO2(g) + 1/2 O2(g) N2O5(s).
N2O5(s) 2 NO(g) + 3/2 O2(g), deltaH = 223.7 kJ
NO2(g) NO(g) + 1/2 O2(g), delataH = 57.1 kJ
delataH = ______kJ
12))))Write all coefficients, even if they are fractions or 1.)
(a) (Apply fractions as needed.)
______ _____(s) + ______ ______ (g) 5 NaCl(s)
(b) (Use the lowest possible coefficients.)
_______ _____ (s) + ______ _____(g) _____CaCl2(s)
(c) (Apply fractions as needed.)
_____ _____(g) _____O3(g)
(d) (Apply fractions as needed.)
______Mg(s) + _____ ______(s) + _____ ____(g) _____Mg3(PO4)2(s)
Answer:
one more time
Explanation:
shpuld i go
Help with 3.A and B image provided below
a. P=0.971 atm=737.6 mmHg
b. n=2.88 x 10⁻³
Further explanationDalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
[tex]\tt P_T=P_1+P_2+..P_n[/tex]
A. vapor pressure of water at 22.5 = 20.4 mmHg
Pt=P H₂ + P H₂O
758 = P H₂ + 20.4
P H₂=737.6 mmHg=0.971 atm
B.Ideal gas Law = PV=nRT
P = 0.971 atm
V = 72 ml = 0.072 L
R = 0.082 L/atm mol
T = 22.5 + 273.15 =295.65
[tex]\tt n=\dfrac{0.971\times 0.072}{0.082\times 295.65}=2.88\times 10^{-3}[/tex]
How many electrons are in the nucleus of an atom with an atomic number of
16?
O None. Electrons are not in the nucleus
08
O 16
O 32
Answer:
None. Electrons are not in the nucleus.
Explanation:
We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus. Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.
Symbol of proton= P⁺
Symbol of neutron= n⁰
The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons. The umber of protons and electrons are always equal to make the atom electrically neutral .
The atom having atomic number 16 have 16 electrons and these electrons are present out side the nucleus.
Determine the wavelength of the energy that needs to be absorbed for a 3p electron in chlorine to be promoted to the 4s subshell. Assume that Zeff=6 for a chlorine atom.
Answer:
The wavelength of the energy that needs to be absorbed = 52.36 nm
Explanation:
For this study;
Let consider the Rydgberg equation from Bohr's theory of atomic model:
i.e.
[tex]\dfrac{1}{\lambda} = R_H (Z^*)^2( \dfrac{1}{n_1^2}-\dfrac{1}{n_2^2})[/tex]
where
Z* = effective nuclear charge of atom = Z - σ = 6
n₁ = lower orbit = 3
n₂ = higher orbit = 4
[tex]R_H[/tex] = Rydyberg constant = 1.09 × 10⁷ m⁻¹
λ = wave length of the light absorbed
∴
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(6)^2( \dfrac{1}{3^2}-\dfrac{1}{4^2})[/tex]
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(36)( \dfrac{1}{9}-\dfrac{1}{16})[/tex]
[tex]\dfrac{1}{\lambda} = 392400000\times0.0486111111[/tex]
[tex]\dfrac{1}{\lambda} =19075000[/tex]
[tex]\lambda = \dfrac{1}{19075000}[/tex]
[tex]\lambda = \dfrac{1}{1.91\times 10^7 \ m^{-1}}[/tex]
[tex]\lambda = 5.236 \times 10^{-8} m[/tex]
[tex]\lambda = 52.36 \times 10^{-9} m[/tex]
[tex]\lambda = 52.36\ n m[/tex]
Therefore, the wavelength of the energy that needs to be absorbed = 52.36 nm
what do y'all girls find attractive on a guy?
Answer:
alot of things
Explanation:
Boron has two isotopes. Boron-10 which has a mass of 10.0129 and Boran-11 with a mass of 11.0093 occurs 52.69% of the time and B - 11 47.31% of the time. What is the average atomic mass of boron?
Help me
Answer:
Copper, a metal known since ancient times, is used in electrical cables and pennies, among other things. ... Calculate the average atomic mass of copper. ... The atomic masses of the two stable isotopes of boron 10B (19.78%) and 11B (80.22%) are 10.0129 amu ... (.1978)(10.0129 amu) + (.8022)(11.0093 amu) =10.81 amu.
Explanation:
I hope I help :)
Why is Mg++ smaller than Mg atom?
Answer:
The magnesium ion is much smaller than the magnesium atom because magnesium atom contains more electrons as compared to magnesium ion. Explanation: ... Whereas when an atom tends to lose an electron then it acquires a positive charge and size of the atom tends to increase.
Answer:
Because it looses it two electrons to form a stable octet Ionic form..........
Mineral reaction to stress
Answer:
Tenacity describes the reaction of a mineral to stress such as crushing, bending, breaking, or tearing. ... The majority of all minerals are brittle. An example is Quartz. (Minerals that are not brittle may be referred to as Nonbrittle minerals.)
Which is a valid reason why total dissolved solids (TDS) cannot be accurately calculated by conductivity alone?
Global warming has significantly increased the conductivity of water.
Big blobs of algae do not conduct electricity.
Fish poop changes the conductivity.
Ionic compounds may behave differently based on ion characteristics (e.g. charge or size).
Some dissolved solids may be nonelectrolytes.
Answer:
The correct option is the last option (Some dissolved solids may be nonelectrolytes)
Explanation:
Total dissolved solids (TDS) cannot be calculated by conductivity alone because conductivity involves ionic charges and there are solids that dissolve in water but do not carry ionic charges (and thus form non-electrolytes). Examples include sucrose (common sugar) and glucose. These two solids will dissolve in water but would not form ions that will carry ionic charges which are responsible for conductivity. Thus, if TDS only depends solely on conductivity, then a solution that contains dissolved sucrose will be wrongly accounted for as the sucrose will be omitted from the dissolved substances.
A valid reason why total dissolved solids (TDS) cannot be accurately
calculated by conductivity alone because some dissolved solids may be
non-electrolytes.
Conductivity means the ability of electric current to pass through a
substance and an electrolyte has a high conductivity when dissolved in
water.
Dissolved solids can't be measured by conductivity because not all
dissolved solids are electrolytes.
Read more on https://brainly.com/question/19457008
Sulfur has an electronegativity of 2.58, while Cesium has a value of 0.79. Based on this information, they would have what kind of chemical bond?
Answer:
Ionic
Explanation:
Because sulphur is a non-metal and cesium is part of the group 1 Alkali Metals, this creates an ionic bond
Ionic bonds are created from one metal and one non-metal element.
This still is declared as Ionic despite the balance of this is Cs2S
pls help!!
The number that represents a neutral pH is ________.
Answer:
7
Explanation:
A very new item just arrived in the market. It is very good for construction, and other things. Now, this item has chemicals, and in every drop, there are 400 grams of NaCI. If there are 10 drops in this item, how many grams of NaCI are in one bottle?
Answer: 4,000 grams of NaCI
Explanation:
We know that there are 400g of NaCI in one drop.
This bottle has 10 drops of this item.
So, we have to multiply the amount of NaCI in a drop by the amount of drops.
400 x 10 = 4,000.
The answer to the question is 4,000. Hope this helps!
Please help I beg you
Answer:
is highly respect is correct I promise!
Hat is the answer for this
Answer:
C
Explanation:
Answer:
I think is A
Explanation:
Hope it helps