Which statement about elements is true?
All substances are made up of elements.
There are approximately 50 elements.
An element is made up of different types of atoms.
Most elements are nonmetal.

Answer:
first one is right.
there are 117 elements, so 2nd option is wrong.
elements are made up of one type of atoms, so 3rd is also wrong.
most elements are metal. so 3rd is wrong
I NEED HELP THIS IS DUE TMR!
A 124.6-g sample of copper has a volume of 14 cm. what is the density of copper?
Answer:
The density of copper is 8.9 grams per cubic centimeter.
Explanation:
There is a writing mistake in statement, correct form is written below:
A 124.6 grams sample of copper has a volume of 14 cubic centimeters. What is the density of copper?
Let suppose that mass of the copper sample is distributed uniformly in its volume, then we shall use the following definition of density ([tex]\rho[/tex]), in grams per cubic centimeter:
[tex]\rho = \frac{m}{V}[/tex] (1)
Where:
[tex]m[/tex] - Mass, in grams.
[tex]V[/tex] - Volume, in cubic centimeters.
If we know that [tex]m = 124.6\,g[/tex] and [tex]V = 14\,cm^{3}[/tex], then the density of the sample of copper is:
[tex]\rho = \frac{m}{V}[/tex]
[tex]\rho = 8.9\,\frac{g}{cm^{3}}[/tex]
The density of copper is 8.9 grams per cubic centimeter.
solid liquid and gas is physical or chemical explain
Answer: Physical change
Explanation: I said physical change because its changing the form of the substance and also solid to gas are sublimating
50 POINTS PLEASE ANSWER CORRECTLY
What happens to the momentum of two cars when they collide?
A. The total momentum after the collision increases.
B. The total momentum after the collision decreases.
C. The total momentum after the collision is equal to the total momentum before the collision.
D. The total momentum before and after the collision is not conserved.
Answer: I honestly think it might be C
Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.
Answer: C. The total momentum after the collision is equal to the total momentum before the collision.
Hope this helps
Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.
What is the name of this compound?
C6H6-
C=O-
H
Answer: Benzaldahyde
Explanation: the C₆H₅- represents the substituted benzene ring and the
CHO should represent the functional group of aldehyde
Answer:
The name of the compound is benzaldehyde
this is due in five mintues please help
Answer:
5
Explanation:
Na, N, O, O, O
34.56 + 42.235 x 0.0123 – 0.001
with correct sig figs
Answer: 35.078 to 3 significant figures
Explanation:
Solving;
34.56 + 42.235 * 0.0123 - 0.001
We solve the multiplication first according to the BODMAS rule.
So,
42.235 * 0.0123 = 0.51949
Doing the addition,
34.56 + 0.51949 - 0.001
This gives;
35.079 - 0.001
And finally the subtraction gives;
= 35.078
120.0 g of 4.0°C water (Specific Heat: 4.184J/g°C) is heated until its temperature is 35°C. Calculate the amount of heat energy needed to cause this rise in temperature?
Answer: I got 15.56
Explanation: I am so sorry if that's wrong but I used the equation Q=m×c×ΔT where
m=mass
ΔT= temp change that occurs
c= specific heat capacity
good luck, again sorry if i totally biffed that
Based on the periodic table, which of the following elements has properties most like neon’s?
A- Boron (B)
B- Hydrogen (H)
C- Fluorine (F)
D- Krypton (Kr)
Answer:
D. Krypton (Kr)Explanation:
because
Neon and Krypton, both are belongs to Inert or Noble gas Group
A boy is skating down the street, hits a curb, and files off the board. Why did this happened? Can y’all plz help me it’s due today!
Answer:
to much sause
Explanation:
Define the law of conservation of charge and provide an example.
Define opposite charges attract and like charges repel and provide an example.
Define Electricity along with an example.
Answer:
Conservation of Charge is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved.
What is the kinetic energy of a rock with a mass of 50 kg and a velocity of 30 m/s?
Answer:
100 thousand dollars bobvieijefn iojef
Explanation:
your mom gae
What are several ways that humans destroy an ecosystem?
Answer:
Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth, overconsumption, overexploitation, pollution, and deforestation, to name but a few.
Explanation:
Hope this helped!!!
How many moles of CaCO3 are needed to dissolve in 0.600 liters to make a
2.25 M solution?
A 0.267 mol
B 3.77 mol
C 1.35 mol
D 2.43 mol
Answer:
1.35 moles of CaCO₃
Explanation:
Molarity, it is a sort of concentration that indicates the amount of moles in 1 L of solution.
M = mol /L
This is a simple equation
M = 2.25 M
Our volume is 0.6L
M . L = mol
Then, 2.25 mol/L . 0.6L = 1.35 moles
We need 1.35 moles of CaCO₃
please help me with these questions, im not understanding :(
Answer:
this is all the answers i hope you have a good day
Explanation:
may i please have a branlliests
What should you use to compare one substance with another substance in a reaction?
Answer:
metal or other acids
Explanation: hope u get it right
A sample of nitrogen gas occupies 1.83 L at 27 °C and 1.000 atm of pressure. What will
the volume be at -100 °C and the same pressure?
Answer:
1.06L = V₂
Explanation:
Charle's Law states that the volume of a gas is directly proportional to the absolute temperature when pressure remains constant.
The equation is:
V₁T₂ = V₂T₁
Where V is volume and T absolute temperature of 1, initial state and 2, final state of the gas.
V₁ = 1.83L
T₂ = -100°C + 273.15 = 173.15K
V₂ = ?
T₁ = 27°C + 273.15 = 300.15K
V₁T₂ = V₂T₁
1.83L*173.15K = V₂*300.15K
1.06L = V₂need the answer to this
Answer:
don't see anything
Explanation:
repost it
Kathy is trying to conduct an experiment she wants an element that is
very reactive, which of these should she use?
What mass of iron (ciron= 0.11 cal/g°C) would need 1450 cal of energy in order to raise its temperature by 19.7°C
Answer: m=Q/c*\Delta TQ/c∗ΔT = 1450cal/(0.11cal/g* 19.7ºC)=669.12 g1450cal/(0.11cal/g∗19.7ºC)=669.12g
Answer: 669.12g iron.
Explanation:
Coke in a Coca Cola bottle has a volume of 500 ml and a mass of 756 grams. What is its density
Answer: 1.11 g/mL is the density
4. Identify What do scientists call a substance that forms during a chemical reaction?
5. Identify On what side of the equation are reactants found?
Answer:
4. Reactant
5. Left
I hope this helps ❤️❤️
Blank is the area of physical science that studies energy and how it acts with matter
Answer:
Physics is a natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the study of nature in an attempt to understand how the universe behaves.
Explanation:
Which chemical equation is a model of a decomposition reaction?
Answer:
The answer is C
It's a model of Decomposition reaction
In the following reaction, the partial
pressure at equilibrium for each of the
products, CO and water vapor at 990°
C, is 11.0 atm and the partial pressure
for each of the reactants, H2 and CO2,
at equilibrium is 8.70 atm. What is Kp?
H2(g) + CO2(g) + H2O(g) + CO(g)
Kp = [?]
Answer:
H2+CO2=H2O+CO
Kp=(pCO)(pH2O)/(pH2)(pCO2)
= 11×11/8.70×8.70
=1.60
A gaseous mixture containing 1.5 mol of Ar and 3.5 mol of CO2 has a total pressure of 7.0 atm . What is the partial pressure of CO2.
Answer:
4.9 atm
Explanation:
Given:
Total pressure = 7.0 atm
(Total number of moles)=[ (1.5 mol arg) + (3.5 mol co2) ]
= 5 moles
Let Partial pressure of CO2 gas = P(CO2)
✓✓partial pressure of CO2 can be calculated using below expresion.
P(CO2) / Total pressure = (moles of CO2 gas) / Total number of moles
✓✓ Let us substitute the values into the above expresion.
[P(CO2) / 7.0 atm ] = [3.5 mol / 5 moles]
P(CO2)= [7 atm × 3.5 moles] / [5 moles]
= 4.9 atm
Hence, the partial pressure of CO2 is 4.9 atm
Answer:
Partial pressure of CO₂ = 4.9 atm
Explanation:
From the question given above, the following data were obtained:
Mole of Ar = 1.5 moles
Mole of CO₂ = 3.5 moles
Total pressure (Pₜ) = 7.0 atm
Partial pressure of CO₂ =?
Next, we shall determine the mole fraction of CO2. This can be obtained as follow:
Mole of Ar = 1.5 moles
Mole of CO₂ = 3.5 moles
Total mole = 1.5 + 3.5
Total mole = 5 mole
Mole fraction of CO₂ = mole of CO₂ / total mole
Mole fraction of CO₂ = 3.5 / 5
Mole fraction of CO₂ = 0.7
Finally, we shall determine the partial pressure of CO₂. This can be obtained as follow:
Total pressure (Pₜ) = 7.0 atm
Mole fraction of CO₂ = 0.7
Partial pressure of CO₂ =?
Partial pressure of CO₂ = mole fraction of CO₂ × total pressure
Partial pressure of CO₂ = 0.7 × 7
Partial pressure of CO₂ = 4.9 atm
What number and types of atoms occur in a formula unit of
Ca(NO3),?
Answer:
help with mine ill help with yours
Answer:
1 calcium atom, 2 nitrogen atoms, and there are 6 oxygen atoms
Explanation:
the formulas of three important acids and three important bases and describe their uses.
Answer:
18929eu9sisjwiejwjxjjejxme
11. Why does cotton absorb so much water?
a. Cotton is adhesive to the water molecules
b. The polarity of water allows it to dissolve cotton.
C. Cotton has hollow fibers that absorb by capillary action
d. Cotton is cohesive to the cotton fibers
Answer:
c
Explanation:
What do you predict might happen if groundwater sources around the world continue to be depleted faster than they are restored?
I'll mark brainliest!