Answer:
Acceleration is :
a = 2.89 m/s2
Explanation:
Acceleration : It is the change in the velocity of the object per unit time.
The object starts from the rest , so the initial velocity of the object is zero.
Initial velocity , u = 0
Final velocity = 100 km/h
Change the velocity to m/s because[ time unit is in second(9.60 s)]
1 km = 1000 m
1 hour = 60 x 60 sec = 3600 sec
v = 27.78 m/s
u = 0 m/s
time = 9.60 s
The acceleration"a" is calculated using :
Answer:
(4) 266 moles
Explanation:
We have Dinitrogen Pentoxide N2O5
6.41*10^25 molecules are given
No of Moles of N2O5 =
=
= 106.5 mol
Now using Unitary Method
2 Mole of Nitrogen pentoxide require 5 mole of Oxygen to form N2O5
1 mole of N =
In 106.5 mole of N = = 266.25 mole
So, 6.41*10^25 molecules of N2O5 will require 266.25 mole of Oxygen atoms.
100%
Physical Property
Color
Density
Boiling Point
Malleability
Temperature
Chemical Property
Flammability
Reactivity with an acid
Reactivity with a base
<em>(here are the other answers i got a 100% so they all should be right)</em>
1. In an electrically neutral atom of any element, there are equal numbers of
A) protons and neutrons.
B) electrons and protons.
C) electrons and neutrons.
D) atomic number and atomic mass.
2. According to theories concerning the origin of life, the atom shown is a likely choice for the basic element of all livings things because it
A) is small and unstable.
B) is relatively stable and can form four covalent bonds.
C) forms four ionic bonds with other elements and itself.
D) is large and takes up enough space to fill the structure of a cell.
3. When Dmitri Mendeleev first developed the periodic table, one of the most important features that he introduced was starting a new row at a certain point. What factor was most important to Mendeleev in knowing when to end a row (period) and start a new one?
A) The reactivity of the elements changed drastically.
B) The state of the elements went from solid to liquid.
C) The boiling point of the elements decreased dramatically.
D) The size of the elements jumped from very large to very small.
4. Which word or group of words is represented by the word "period" in the term Periodic Table?
A) Group
B) Family
C) Energy Level
D) Valence Electrons
5. Members of the alkaline earth elements have several things in common. They are
A) nonmetals and are nonreactive.
B) metals with two valence electrons.
C) metals that are not very reactive.
D) metalloids with two valence electrons.
6. During a reaction, a halogen chemically combines with a Group 1 element to form a compound. How does this reaction occur, based on the atomic structure of each element?
A) A halogen atom loses an electron to an atom of a Group 1 element.
B) A halogen atom gains an electron from an atom of a Group 1 element.
C) A halogen atom loses two electrons to an atom of a Group 1 element.
D) A halogen atom shares an electron with an atom of a Group 1 element.
7. Mendeleev noticed that if he organized the elements by atomic weight certain patterns emerged. For instance, elements in the same group (family) appeared to have the same
7
A) valence.
B) melting point.
C) isotopic ratio.
D) number of neutrons.
8. Sodium has an atomic number of 11 and has a net charge of 0. When sodium combines with chlorine, it has a net charge of +1. Why?
A) Sodium loses a negative electron when forming chemical bonds.
B) Sodium gains a + proton when forming chemical bonds.
C) Sodium loses a + proton when forming chemical bonds.
D) Sodium shares a negative electron with chlorine.
9. The element sodium has an atomic number of 11 and a mass number of 23. How many protons, neutrons, and electrons does one atom contain?
A) 11p+, 11e-, 12no
B) 11p+, 12e-, 11no
C) 11p+, 11e-, 23no
D) 12p+, 12e-, 11no
10. Using the chart above, determine which statement would be FALSE.
A) Carbon would have 6 protons.
B) Hydrogen would have 0 neutrons.
C) Each element would have a mass number of 12.
D) Neon is the element with an atomic number of 10.
11.Consider this row in the periodic table of elements. As we move from left to right, across the row, the elements
A) change from nonmetals to metals.
B) change from metals to nonmetals.
C) start as gases but end as solids.
D) show a decrease in atomic mass number.
12.Consider the elements in the periodic table. The stair-step line between the pink squares and the yellow squares separates the ___________ (pink) from the _____________ (yellow).
A) gases; solids
B) metals; nonmetals
C) nonmetals; metals
D) reactive; non reactive
13. C-14 is an isotope of the element carbon. How does it differ from the carbon atom seen here?
A) C-14 has two more protons.
B) C-14 has two more neutrons.
C) C-14 has a larger atomic radius.
D) C-14 has two additional valence electrons.
14. Elaborate what knowing that carbon-14 has an atomic number of 6 tells us about the atom.
A) Carbon-14 contains 6 baryons, 7 prions, and 8 neutrons.
B) Carbon-14 contains 7 electrons, 7 protons, and 7 quarks.
C) Carbon-14 contains 6 electrons, 6 protons, and 8 neutrons.
D) Carbon-14 contains 8 electrons, 6 photons, and 6 neutrons.
15. Many people believe that the atomic number of the atom is the number of electrons in the atom. Describe when this is the case.
A) As the atom absorbs photons the electrons excite and produce unique emission spectrum.
B) Through radioactive decay the electrons and neutrons form unique atomic number isotopes.
C) When the atom is neutral and the number of electrons and the number of protons are equal.
D) Whether the atom is neutral or charged the number of electrons is always a unique identifier.
