Answer:
80mg
Explanation:
Given parameters:
Density of Platinum metal = 21.4g/mL
Dimension of the metal = 3cm by 0.03m by 40mm
Unknown:
Weight of the metal in milligrams?
Solution:
Density is the mass per unit volume of a substance.
Mathematically;
Density = [tex]\frac{mass}{volume}[/tex]
Volume of the platinum metal = l x w x h
Let us convert the dimension of the metal to the same unit;
3cm x 0.03m x 40mm
convert to cm;
100m = 1cm
0.03m = [tex]\frac{0.03}{100}[/tex] = 0.0003cm
-- 40mm;
1mm = 0.1cm
40mm = 40 x 0.1 = 4cm
Volume of the metal = 3 x 0.0003 x 4 = 0.0036cm³
1mL = 1cm³; so volume = 0.0036mL
Mass of the metal = 21.4 x 0.0036 = 0.08g
1g = 1000mg
0.08g = 0.08 x 1000 = 80mg
0.28gram of NH3 on decomposition gave 0.25gram of nitrogen and hydrogen. Find the volume of hydrogen evolved at Ntp. (2gram hydrogen at NTP= 22.4liter)
The volume of H₂ evolved at NTP=0.336 L
Further explanationReaction
Decomposition of NH₃
2NH₃ ⇒ N₂ + 3H₂
conservation mass : mass reactants=mass product
0.28 NH₃= 0.25 N₂ + 0.03 H₂
2 g H₂ = 22.4 L
so for 0.03 g :
[tex]\tt \dfrac{0.03}{2}\times 22.4=0.336[/tex]
Predict what would happen if a positive charge is placed between the two charges and allowed to move. Explain.
Answer: The same effect happens when you put two electrons near each other (or two protons). We know that if you have a single positively charged particle, a positively .
Explanation: i hope that helped. have a good day.
The density of mercury is 13.6 g/ml. What is the volume of 386g of mercury?
The density of mercury is 13.6g/lmL. The volume of a 200 gram sample of mercury will be :
Volume=
200g/13.6g/mL
Volume=14.7mL
Therefore the correct option will be E
“Selective” means to pick and choose; “permeable” means objects can pass through something. Do you think cell membranes are “selectively permeable”? Give evidence to support your answer.
This is due at 4 p.m.
Answer:
yes the cell membranes are semi permeable
Choose the statement that is NOT true.
Hundreds of stars with planets have been confirmed using the radial velocity method and the transit method.
The first Earth-size planets ever found outside the solar system were discovered in 2012 by the Kepler Mission team.
Planets orbiting stars in the "habitable zone" are likely to have life existing on them.
More than 50% of the 100 billion stars in the Milky Way galaxy have at least one planet orbiting.
Answer:
More than 50% of the 100 billion stars in the Milky Way galaxy have at least one planet orbiting.
Explanation:
This is False so this would be your Answer
Answer: planets orbiting stars in the habitabke zone are likely to have life existinv on them
Explanation:
because it is false and i took the quiz
Which term describes the amount of order in a system
Answer:
entropy
Explanation:
HELP! HELP!
an element with 5 protons, and 8 electrons has an atomic number of?
Answer:
Explanation: 15
HELPPP OMG THIS IS SO HARD ITS FOR SCIENCE LOL
Answer:
The nucleus of the atom contains two subatomic particles, the protons which are positively (+) charged and the neutrons which are neutral (no charge).
Explanation:
Which statement describes a reason people must protect mineral resources?
A.
Minerals are used in only a few products.
B.
Mining has no effect on the natural surroundings.
C.
Minerals are pretty to look at but rarely useful.
D.
There is a limited amount of each mineral available.
Answer:
The answer is D
Explanation:
1. Which of the following is an example of a chemical reaction? *
O A. mixing lemonade powder with water
O B. burning marshmallows over a fire
O C. melting butter in a pan
D. boiling water on a stove
Answer:Burning marshmellows over fire
Explanation:
Explain why the Earth has four different seasons
Answer:
Earths rotation
Explanation:
Answer:
because if there was not four diferent season we would not have a day or a night because we would not be moving
Explanation:
Which type of bond is salt? a. covalent b. valence c. metallic d. ionic
Answer:
D. Ionic
Explanation:
It has ionic bonding! Good luck ^^
What effect does the spinning of the earth's core have?
A.it creates gravity
B. it creates matter
C. it creates mass
D. it creates the earths magnetic field.
Answer:
c
Explanation:
its c
Earth contains a spinning electric filed. The spinning of earth core creates its magnetic field. Thus, option D is correct.
What is a spinning body?A body which rotates in its own axis is called a spinning body. Earth rotates about its along with revolving around sun. The outer core of earth generates electric current. This is called telluric current.
Flow of this current creates an electric current which is parallels to the surface of earth. The direction of magnetic field lines will be perpendicular to the direction of current. But it comes stronger when parallel to current.
A rotating electric current results in the generation of a magnetic field. Thus spinning of earth core generates a magnetic field and therefore, option D is correct.
To learn more about magnetic field, refer the link below:
https://brainly.com/question/11514007
#SPJ2
Answer this easy science question for brainiest
First come first served:)
Answer:
The nucleus is a collection of particles called protons, which are positively charged, and neutrons, which are electrically neutral.
Explanation:
Answer:
the person above me is right
hope you do good on your test
Explanation:
7th grade help me plzzzzzzz
Answer:
15 atoms
increases
Explanation:
10 hydrogen atoms + 5 oxygen atoms = 15 atoms
Which statement describes the Loyalists in North Carolina during the colonial era? They were mostly wealthy and educated. They were also known as Whigs. They wanted to be free of British rule. They wanted to remain part of Britain.
Answer:
D) They wanted to remain part of Britain
Explanation:
i took the test lol
Answer:
D
Explanation:
What is the mass of an atom with 44 protons, 42 electrons, and 57 neutrons?
Answer:
The atomic mass is 101.
Explanation:
Protons and neutrons are the only particles that contribute to mass. Electrons do have a mass, but it's so miniscule and insignificant that it doesn't contribute to the mass of an atom. In every instance of calculating atomic mass, add the number of protons to the number of neutrons.
Therefore,
44 + 57 = 101
number of protons + number of neutrons = atomic mass
Also, there can never be a negative amount of protons or neutrons, so if you get a negative number, there's something wrong.
Bonus Information:
Don't confuse mass with charge! As it says in its name, neutrons are neutral or have no charge. Protons (+) and electrons (-) are the only particles that have a charge, so calculating that would be different.
If you were calculating the atomic charge with the same numbers, your answer would be:
44 - 42 = 2
Charge = +2
What To Remember:
M = p + n
C = p - e
C = atomic charge, M = atomic mass, p =protons, n = neutrons, e = electrons
I hope this helps!
plsssssssssssssssssssssssssssssssssssssssss help me
Answer:
C
Explanation:
A year is a complete revolution around the Earth
Plate movement is thought to be the result of what
Answer: Plate movement is thought to be driven by a combination of the motion of the seafloor away from spreading ridges due to variations in topography and density changes in the crust.
Hope this helps
Select the correct answer
Giving brainliest
Answer: is C&A
Explanation:the electric motor converts electricity in to mechanical energy
the electric generator converts mechanical energy to electricity so it could not be D.
and they don't use batteries as their main source of power so it could not be B.
hence forth it is C&A
HOPE THIS HELPS!!!!!!1
PLEASE MARK BRAINLIEST!!
Which of the following might be included in a chemical
reaction?
a Molecules
b lons
C Pure elements
d All of the above
Answer:
D. All of the above
Explanation:
Molecules, ions, and pure elements might be included in a chemical reaction. Therefore, option (d) is correct.
What is a chemical reaction?A chemical reaction can be described as a reaction that brings the chemical conversion of one chemical substance to another chemical substance. The reactions cause chemical changes that include the rearrangement of electrons in order to create and break bonds between atoms.
The compound or molecules which are primarily utilized in a reaction are called reactants. Chemical reactions give products, which possess characteristics different from the reactants of the reaction.
Chemical reactions take place at a definite rate of reaction at a given concentration, temperature, and pressure. The rate of reaction increases with the rising temperature of the reaction as more activation energy is available for reactant molcules collisions.
Therefore, in a chemical reaction reactants and products can be present as Molecules, ions, and pure elements.
Learn more about Chemical reactions, here:
brainly.com/question/22817140
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Among the groups of elements listed below, which have the same number of electrons in their outermost energy levels?
O NP. As, Sb
None of these
OK, Ca, Rb, Sr
OLI, B, C F
O Na Mg, ALS
Answer:
N, P, As, Sb
Explanation:
Elements present in the same group having same number of valence electrons. The first option is correct from given options because nitrogen, phosphorus, arsenic and antimony are present in same group thus having same number of electrons in outer most energy level.
Electronic configuration of N:
N₇: [He] 2s² 2p³
Electronic configuration of P:
P₁₅: [Ne] 3s² 3p³
Electronic configuration As:
As₃₃: [Ar] 3d¹⁰ 4s² 4p³
Electronic configuration Sb:
Sb₅₁: [Kr] 4d¹⁰ 5s² 5p³
Here it is clear from electronic configuration all these elements have five number of valence electrons.
The atomic weight of magnesium is 24.What does that mean?
Answer:
because a 24Mg atom has 12 neutrons in its nucleus
24H2S + 16HNO3 3Sg+ 16NO + 32H2O
Answer:
24 sultur with 48hydrogen+16 hydrogen,nitrogen and 48 oxygen+16 nitrogen,16 oxygen+62hydrogen and 32 oxygen
Explanation:
A student is able to lift 500N weight by applying 100N. What is the mechanical advantage of a simple machine?
Explanation:
Load=500N
Effort=100N
Now,
We have,
Mechanical advantage= Load / effort
= 500/100
=5
Therefore, mechanical advantage is 5.
Plsss helpppp
im confused
will mark BRAINLIEST
Answer:
I searched the answer up on Brainly so its not my credit.
Explanation:
The answers D.
"If you have learned that metal + nonmetal ⟶ ionic bond, the answer is D, because N and C are the only pair of nonmetals.
However, if you have learned that a bond is ionic if the electronegativity difference (ΔEN) between the two atoms is greater than 0.7, the answer is A, B, and D.
The Li-Cl bond is definitely ionic.
For Na and C, ΔEN =1.62, so the Na-C bond is a highly polar covalent bond.
For Mg and C, ΔEN = 1.24, so the Mg-C bond is a polar covalent."
Hope this helps :D
Fill in the blanks: ______ compounds break up into ______ and ______ in solution, which can move freely and carry an _______ current.
I hate virtual school
please help ASAPPP
will mark brainliest!!!
The polyatomic ions are those ions which has more than two atoms involved such as the other options than OH^-1 in the question. The OH^-1 ion is the diatomic ion because it has only 2 atoms
______________________________________HOPE IT HELPS!Is the average atomic mass of a sample containing three lithium-6 and two lithium-7 closer to the mass of Li-6 or Li-7 ?
The average atomic mass of a sample closer to the mass of Li-6
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
Mass atom X = mass isotope 1 . % + mass isotope 2.%
three Li-6, mass number = 6
two Li-7, mass number = 7
total abundance = 5
abundance for Li-6 =
[tex]\tt \dfrac{3}{5}\times 100\5=60\%[/tex]
abundance for Li-7 =
[tex]\tt \dfrac{2}{5}\times 100\5=40\%[/tex]
Average atomic mass :
[tex]\tt (0.6\times 6)+(0.4\times 7)=6.4[/tex]
What is the name of the following atoms?
An atom with 3 protons and 4 neutrons what is the name?
Answer:
an atom with 3 protons and 4 neutrons is a lithium atom