Answer:
Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color change, formation of a precipitate, formation of a gas, odor change, temperature change.
Answer:
Change in Color
Heat is released (bubbles in solution)
Sometimes even a change in texture
A new smell
Formation of a precipitate
The blood must keep moving round the body to keep the rate of diffusion high explains why
Answer:
red blood cells and diffusion.
Explanation:
this process involves red blood cells and diffusion. Red Blood cells (RBCs) are a type of blood cell whose role is to transport oxygen from the lungs to the peripheral tissues of the body. Oxygen diffuses from the alveoli of the lungs in to the RBC's, where it binds to hemoglobin.
Diffusion is a very important process within the human body and is essential to the transport of molecules within a number of organs including the lungs, kidneys, stomach and eyes. The lungs process millions of tiny air sacs that are called alveoli, each of which are in close contact with capillaries.
2 A. Explain why these elements are all placed in Period 3 of the Periodic Table.
Answer:
which elements??? more info please
11. If two substances react and the temperature of the mixture decreases, the reaction
is a) Endothermic
b) Never going to happen unless it is heated
c) Exothermic
d) one that causes atoms to be destroyed
Answer:
a.endothermic reaction
PEASE RESPOND QUICKLY WILL GIVE BRAINLIST!!!!!!!!
Which of the following polyatomic ions will form an ionic compound with a single sodium ion? (5 points)
A.)CO32−
B.)PO43−
C.)SO42−
D.)NO31−
Answer:
D).
[tex]{ \tt{NO_{3} {}^{ - } }}[/tex]
Explanation:
The nitrate ion because it is a radical with a valence of 1, forming sodium nitrate.
[tex]{ \tt{Na {}^{ + } .NO _{3} {}^{ - } }}[/tex]
The polyatomic ion that does form an ionic compound with a single sodium ion (Na^+) is NO3^- .
A polyatomic ion is an ion that contains more than one atom. Recall that an ion is any chemical specie that contains a positive or negative charge. Sodium is a member of group 1 and forms a univalent positive ion.
The polyatomic ion that does form an ionic compound with a single sodium ion (Na^+) is NO3^- and the compound is NaNO3.
Learn more: https://brainly.com/question/8592296?
12. Organelles allow eukaryotic cells to carry out more functions than prokaryotic cells.
True or false?
Answer:
True po
Explaination :
I hope it helps
How many oxygen atoms are in the products of the balanced reaction below?
3Ca + 2AIPO4 + 2Al + Ca3(PO4)2
A. 12
B. 8
C. 3
D. 4
Answer:
B
Explanation:
production ca3(PO4)2
4x2=8
7. A sample of a compound that contains only chlorine and oxygen reacts with excess hydrogen to produce 0.233 grams of hydrochloric acid and 0.403 grams of water. Determine the empirical formula of this compound.
Answer:
ClxOy + H2 > HCl + H2O
HCl = 0.233/37 = 0.006 mol H2O = 0.403/180.02 mol
HCl = 0.006/0.022 H2O = 0.022/0.006
= 1 = 4
Cl2O4 + 5H2 > 2HCl + 4H2O
I'm think that's the answer
What is the final velocity of a 3 kg object that starts with a 5 m/s velocity due to a 2 N force acting over 3 seconds?
Answer:
V= 13 m/s
Explanation:
We're asked to find the magnitude of the object's velocity after a force is applied for
3
s
parallel to its motion.
We'll call the direction it's moving the positive
x
-axis, and the direction of the applied force the positive
y
-axis.
The components of the initial velocity are
v
0
x
=
5
m/s
v
0
y
=
0
(It's moving at
5
meters per second in the straight line we called the
x
-axis.)
We know the object's mass is
3
kg
, and the force applied is
12
N
in the positive
y
-direction. The magnitude of the constant acceleration is thus
a
y
=
∑
F
y
m
=
12
l
N
3
l
kg
=
4
m/s
2
Since this acceleration is directed upward, and the initial
y
-velocity is
0
, we can use the kinematics equation
v
y
=
v
0
y
+
a
y
t
to find the
y
-velocity after
3
seconds.
Plugging in known values, we have
v
y
=
0
+
(
4
l
m/s
2
)
(
3
l
s
)
=
12
m/s
No acceleration was applied in the
x
-direction, so it's
x
-velocity remains
5
m/s
. The magnitude of the velocity is thus
v
=
√
(
v
x
)
2
+
(
v
y
)
2
=
√
(
5
l
m/s
)
2
+
(
12
l
m/s
)
2
=
13
m/s
A student added magnesium hydroxide to a solution of hydrochloric acid. What is the
correct balanced chemical equation?
Answer:
bleh
Explanation:
Neutralization reaction between magnesium hydroxide and hydrochloric acid Mg(OH)2(s) + 2HCl(aq) → 2H2O(l) + MgCl2(aq) b.
so uh pretty sure Mg(OH)2(s) + 2HCl(aq) → 2H2O(l) + MgCl2(aq) b.
correct me if im wrong <3
Hello, Flashligh explain where the energy comes from and how it is affecting change or putting an object in motion
Answer:
Our energy supply comes mainly from fossil fuels, with nuclear power and renewable sources rounding out the mix.
The energy associated with an object's motion is called kinetic energy. Kinetic energy is the energy of motion. All moving objects have kinetic energy
Explanation:
Answer:
Kinetic energy is the energy of motion. All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward. As he winds up and releases the ball, the stored energy is changed into kinetic energy, the energy of motion!So that , energy comes from and how it is affecting change or putting an object in motion.
Explanation:
I ain't flashligh
Which of the following are examples of electromagnetic waves?
A.thunder, singing, tsunamis
B.sound, tsunamis, earthquakes
C.light, microwaves, radiation
Answer:
C
Explanation:
Electromagnetic waves travel at the speed of light and do not require molecules (gas, solid or liquid) to vibrate and travel.
Soundwaves when singing or from thunder vibrate particles to reach our ears and are known as mechanical waves.
You have 2.7 moles of carbon. How many atoms do you have?
Answer:
1.63 × 10²⁴ atoms.
Explanation:
To calculate the number of atoms (N) contained in 2.7moles of carbon, we multiply the number of moles (n) by Avogadro's number (6.02 × 10²³).
That is, N = n × nA
Where;
N = number of atoms
n = number of moles (mol)
nA = Avogadro's numbe
N = 2.7 × 6.02 × 10²³
N = 16.254 × 10²³
N = 1.63 × 10²⁴ atoms.
Hence, there are 1.63 × 10²⁴ atoms in 2.7moles of Carbon.
How does an atom behave if it has a full octet of valence electrons?
O A. It is very stable.
O B. It is very reactive.
O c. It is unpredictable.
O D. It is a gas.
Answer:
A) Very stable.
Explanation:
A valence electron ring takes up to 8 valence electrons. If it has full rings, it is stable.
Which statement describes the energy conversion that takes place durin
photosynthesis?
A. Plants convert chemical energy to solar energy.
B. Plants convert kinetic energy to chemical energy.
C. Plants convert solar energy to chemical energy.
D. Plants convert solar energy to kinetic energy.
Answer:
C
Explanation:
Photosynthesis is use of light(photo---solar energy) to make(synthesize) food(chemical energy) and is done by producers(plant)
Calculate the poH of a solution at 25°C which contains
1 x 10^-10 M of hydronium ions.
Answer:
4.000 hope this helps :)
Anhydrous aluminium chloride contain 20.2% by mass of aluminium show that the emprical formula for anhydrous aluminium chloride
Answer:(d) has a high melting point because it has a giant covalent structure ... (i) Calculate the maximum mass of propyl ethanoate that can be made from 7.20 g of ethanoic ... (c) Anhydrous aluminium chloride contains 20.2% by mass of aluminium. (i) Show that the empirical formula for anhydrous aluminium chloride is A
Explanation:
Which of these is a measure of the average kinetic energy of the molecules of a material? A.heat B.temperature C.thermal energy D.bonding energy
Answer:
b temperature
Explanation:
Temperature is a measure of the average kinetic energy of the particles in a substance
What kind of pattern can you see about elements in the same period with respect to electron
structures?
Answer: A pattern of same atomic orbitals can be seen about elements in the same period with respect to electron structures.
Explanation:
The horizontal rows in a period table are called periods.
Elements present in the same period will have same atomic orbitals.
For example, electronic distribution of Na is 2, 8, 1 and it is a third period element.
Similarly, electronic distribution of Cl is 2, 8, 7 and it is also a third period element.
Hence, both Na and Cl will have K, L, M shells, that is, they have three atomic orbitals.
Thus, we can conclude that a pattern of same atomic orbitals can be seen about elements in the same period with respect to electron structures.
Can someone pls help I need this quick
Zinc has been added to dilute sulphuric acid. The two react together and a gas bubble forms. The gas that forms is hydrogen. Prove why the gas is hydrogen.
Answer:
Here's your answer
Explanation:
When we insert a burning matchstick near the mouth of gas jar the matchstick burns with a pop sound and produces a blue flame. This proves that the gas collected is hydrogen.
hope it helps
Which particles are attracted as a result of the electrostatic force?
A. Protons and electrons
B. Any particles that have mass
C. Any particles that have like charges
D. Protons and neutrons
Answer:
A. Protons and electrons
Complete the table by writing the name or formula of each compound and the type of bonding that it uses. You may refer to this list of polyatomic ions.
Explanation:
Dinitrogen monoxide: covalent bond
copper(||) hydroxide: ionic bond
Butane: Covalent Bond
Answer
Disulfur decafluoride S2F10 covalent
calcium sulfide CaSO3 ionic
Diphosphorus tetraiodide P2I4 ionic
dinitrogen monoxide N2O ionic
Aluminum chloride AlCl3 covalent
copper(II) hydroxide Cu(OH)2 ionic
barium sulfate BaSO4 covalent
butane C4H10 covalent
Explanation:
edmentum
Students measuring the mass of a substance record 1.127 g, 1.214 g, 1.304 g, and 1.184 g. Which other measurement of the substance's mass would be most precise?  A. 1.514 g  B. 1.205 g  C. 1.416 g  D. 1.384 g
Answer:1.205g
Explanation:
Question 1 of 10
What does a low number on the pH scale say about a solution?
O A. The solution is an acid,
O B. The solution is changing.
O C. The solution is a base.
O D. The solution sg neutral.
Performance Task #4.3
If you will cross a parent with black eye color (BB) and the other is
brown eye (bb), what will be the color of the eyes of their offspring?
BB
b
b
Ex. Rr - Round
Ir - oblong
Genotypic Ratio:
BB
bb-
%
R
rrr
rr
Phenotypic Ratio:
%
Rr
re
Genotypic Ratio:
50% Rr
Bb
b
b
50% IT
Phenotypic Ratio: 50% round
50% oblong
Bb -
bb-
Genotypic Ratio:
%
%
Phenotypic Ratio:
(continuation at the back)
%
I need answers pls, help me brainliest ko po maka ans ng tama, report nonsense thanks.
Answer:
The offspring are all black eye colored.
Explanation:
Since we have genes BB for black eye color and genes bb for brown eye color, crossing the genes, the resulting genotypes in the offspring is Bb, Bb, Bb and Bb. We note that all the genes have the dominant B gene. Since the black eye color dominant gene is present in all the offspring, the offspring are thus all black-eye colored.
So, If you will cross a parent with black eye color (BB) and the other is
brown eye (bb), the offspring are all black eye colored.
In a mass spectrum, there are two peaks, one at m/z 63.0 with percentage abundance 69.1% and another peak at m/z 65.0 with percentage abundance 30.9%. Determine the relative atomic mass (Ar) for this element, giving the answer to 3 significant figures (no units required).
Explanation:
hope the picture above help u understand:)
The relative atomic mass (Ar) of this element is approximately 63.6 (to three significant figures).
To determine the relative atomic mass (Ar) of the element, we use the following formula:
Ar = (m₁ × % abundance1 + m₂ × % abundance2) / 100
Where:
m₁ and m₂ are the masses of the isotopes (peaks) in the mass spectrum,
% abundance1 and % abundance2 are the percentage abundances of the corresponding isotopes.
Given information:
Peak at m/z 63.0 with a percentage abundance of 69.1%.
Peak at m/z 65.0 having a percentage abundance of 30.9%.
Calculate the weighted average mass of the element's isotopes.
Ar = (63.0 × 69.1 + 65.0 × 30.9) / 100
Ar = (4347 + 2009.5) / 100
Ar = 6356.5 / 100
Ar ≈ 63.565
Noe, let's round the calculated mass to three significant figures.
Ar = 63.6
So, the relative atomic mass (Ar) of this element is approximately 63.6 (to three significant figures). This means that the average mass of the element's atoms is approximately 63.6 times the mass of one-twelfth of a carbon-12 atom, which is the standard reference for atomic masses.
To know more about relative atomic mass here
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A student hypothesized that the amount of sunlight a sunflower plant receives determines the number of sunflower seeds the plant produces. In his experiment,
the number of seeds produces is the
Manipulated variable
ЕОООО
Control variable
Dependent variable
Independent variable
Answer:
Dependent variable
Explanation:
In every experiment, there must be a dependent variable and an independent variable.
The independent variable is that variable that you have to manipulate in order to receive a response. E.g, in the experiment described in the question, the amount of sunlight a sunflower plant receives is the independent variable.
The dependent variable is the number of seeds produced. It is the response obtained by carefully manipulating the amount of sunlight
Which of the following is a nonrenewable energy source? O A. Solar B. Hydroelectric C. Natural gas D. Biomass
Answer:
C. natural gas
Explanation:
Solar comes from the sun, which if it became nonrenewable, we would be dead. hydroelectric comes from water and Dams, which water is reproduced through rain. Biomass are things like leaves, which are seasonally reproduced.
4. A piece of metal weighing 0.0713 g was placed in a eudiometer containing dilute aqueous HCl. After the metal fully dissolved, 23.5 mL of hydrogen gas was collected by displace-ment of water and a 400 mm column of water was observed. The water temperature was 258C and the barometric pressure was 758.8 mm Hg (torr). Refer to the Introduction and data sheet to solve the following problems. a) What is the vapor pressure of the water vapor in the column? (Consult Appendix E.)
Complete Question
4. A piece of metal weighing 0.0713 g was placed in a eudiometer containing dilute aqueous HCl. After the metal fully dissolved, 23.5 mL of hydrogen gas was collected by displace-ment of water and a 400 mm column of water was observed. The water temperature was 258C and the barometric pressure was 758.8 mm Hg (torr). Refer to the Introduction and data sheet to solve the following problems.
a) What is the vapor pressure of the water vapor in the column? (Consult Appendix E.)
b) What is the pressure of the water column expressed in mm Hg (torr)? The density of mercury is 13.6 g/mL.
c) Calculate the pressure of the hydrogen gas above the water in the column.
d) Calculate the volume occupied by the hydrogen gas at STP.
Answer:
a) [tex]25\textdegree C=23.8 torrs[/tex]
b) [tex]P_w=758.8[/tex]
c) [tex]P_w=758.8=735torr[/tex]
d) [tex]V_2=20.82mL[/tex]
Explanation:
From the question we are told that:
Metal weight [tex]M_m=0.0713g[/tex]
Volume Hydrogen [tex]V_h=23.5mL[/tex]
Displace-ment Column of water 400 mm column of water
Temperature [tex]T =258\textdegree C[/tex]
Barometric Pressure [tex]p=758.8mmHg[/tex]
Vapour Pressure of water at [tex]25^oC[/tex]
Generally from (Consult Appendix E.)
a)
Va-pour Pressure of water at
[tex]25\textdegree C=23.8 torrs[/tex]
b)
Pressure of Water column
[tex]P_w=758.8[/tex]
c) Pressure of Water column (Consult Appendix E.)
[tex]P_w=758.8=735torr[/tex]
d)
Generally the equation for ideal gas is mathematically given by
[tex]\frac{p_1v_1}{T_1}=\frac{p_2v_2}{T_2}[/tex]
Therefore
[tex]V_2=\frac{p_1V_1T_2}{T_1p_2}[/tex]
[tex]V_2=\frac{735*23.5*273}{298*760}[/tex]
[tex]V_2=20.82mL[/tex]
List two possible steps where impurities may be gained, which would appear to be an increase in copper
yield (why you may get more than 100% of the copper back at the end). Be specific about the steps and
how they might add impurities.
Answer:
i) During washing
ii) During Measurement
Explanation:
The two possible steps are :
i) During washing : during the washing method the residue may be not completely dried out and this residue ( water) will add up to the final product ( copper yield ) and this kind of error is called human error.
ii) During measurement : If the weighing instrument is faulty there might be addition in value of the final copper yield which will see the final yield value > 100% . this error occurs when the initial value and final value is been weighed
help me with this attachment please
Answer:
See explanation
Explanation:
Let us recall that the basic rule in writing balanced chemical reaction equations is that the number of atoms of each element on the right hand side of the reaction equation is the same of the number of atoms of the same element on the left hand side of the reaction equation.
The reaction of red hot iron and steam is written as follows;
3Fe + 4H2O → Fe3O4 + 4H2.
The decomposition reaction of ammonium dichromate is written as;
(NH4)2Cr2O7 → N2 + Cr2O3 + 4H2O
Reaction of aluminium, sodium hydroxide and water is as follows,
2Al + 2NaOH + 2H2O ----> 2NaAlO2 + 3H2
Reaction of potassium bicarbonate with sulphuric acid;
2KHCO3 + H2SO4 -------> K2SO4 + 2H2O + 2CO2
Reaction of zinc and sodium hydroxide is as follows;
Zn + 2NaOH→Na2ZnO2 + H2