Question

1. How are science and technology related? (1 point)

Technology is a branch of natural science.
Science is a branch of technology.
Advances in science may lead to advances in technology and vice versa.
Science is the study of technology.
2. Which of the following is the best reason that scientific models are used? (1 point)
They prove scientific theories.
They help visualize things that are very complex, very large, or very small.
They provide a concrete view of something abstract.
They precisely mimic something in nature.
3. Timers at a swim meet used four different clocks to time an event. Which recorded time is the
most precise?
(1 point)
55 s
55.2 s
55.25 s
55.254 s
4. If the relationship between the manipulated variable and the responding variable is a direct
proportion, what will a line graph of this relationship look like?
(1 point)
a straight line
a curved line
a jagged line
none of the above
5. Which of the following is NOT a pure substance? (1 point)
milk
oxygen
water
carbon dioxide
6. Water is a compound because it (1 point)
can be broken down into simpler substances.
always has two hydrogen atoms for each oxygen atom.
is made of water atoms joined together.
both a and b
7. Which of the following is a heterogeneous mixture? (1 point)
water in a swimming pool
sugar water
a jar of mixed nuts
stainless steel
8. Filtration can be used to separate mixtures based on (1 point)
their boiling points.
their densities.
their melting points.
the size of their particles.
9. Which of the following is a physical change? (1 point)
sawing a piece of wood in half
burning a piece of wood
rust forming on an iron fence
a copper roof changing color from red to green
10. Which of the following is a clue that a chemical change has occured? (1 point)
Iron changes color when heated.
Gas bubbles form in boiling water.
Balls of wax form when melted wax is poured into ice water.
A gas forms when vinegar and baking soda are mixed.
11. Forces of attraction limit the motion of particles most in (1 point)
a solid.
a liquid.
a gas.
both b and c
12. Which of the following will cause a decrease in gas pressure in a closed container? (1 point)
lowering the temperature
reducing the volume
adding more gas
both a and b
13. If a solid piece of naphthalene is heated and remains at 80°C until it is completely melted, you
know that 80ºC is the
(1 point)
freezing point of naphthalene.
melting point of naphthalene.
boiling point of naphthalene.
both a and b
14. During which phase change does the arrangement of water molecules become more orderly? (1 point)
melting
subliming
boiling
condensing
15. The phase change in which a substance changes from a solid to a gas or vapor without
changing to a liquid first is
(1 point)
sublimation.
deposition.
vaporization.
melting.
16. Which phase change is an endothermic change? (1 point)
condensation
vaporization
deposition
freezing
17. How was Bohr’s atomic model similar to Rutherford’s model? (1 point)
It assigned energy levels to electrons.
It described electron position in terms of the electron cloud model.
It described how electrons gain or lose energy.
It described a nucleus surrounded by a large volume of space.
18. What is the difference between an atom in the ground state and an atom in an excited state? (1 point)
The atom in the ground state has less energy and is less stable than the atom in an excited state.
The atom in an excited state has one fewer electron than the atom in the ground state.
The atom in an excited state has more energy and is less stable than the atom in the ground state.
The atom in an excited state has one more electron than the atom in the ground state.
19. The usefulness of Mendeleev’s periodic table was confirmed by (1 point)
the discovery of subatomic particles.
its immediate acceptance by other scientists.
the discovery of elements with predicted properties.
the discovery of the nucleus.
20. The atomic mass of an element is (1 point)
the sum of the protons and electrons in one atom of the element.
twice the number of protons in one atom of the element.
a ratio based on the mass of a carbon-12 atom.
a weighted average of the masses of an element’s isotopes.

Answer 1

Step-by-step explanation:

1.Technology is an application of science through use of modern scientific tools.

2.They provide a concrete view of something abstract. They are also applicable to gain an understanding of better process and systems.

3.C.55.25s

4. A. straight line graph.

5. A. Milk. A pure substance consist of a single element or compound.

6.B. it has two hydrogen atom to one oxygen atom

7.B. Sugar water.

8.D.Size of their particles.

9.A.sawing a piece of wood into half.

10.A..iron changes colour when heated.

11.A.solid

12.A. Lowering the temperature, which lead to increase in gas volume according to. Boyle's law.

13.C. boiling point of naphthalene.

14.freezing,which is the mostly orderly point of water because water moves from liquid to solid state.

15.A.sublimation.

16.B.Vaporisation.

17.C.it is described by a nucleus surrounded by a large volume is space.

18. The atom in the excited state has more energy and is less stable than atom in the ground state.

19.The discovery of elements with predicted properties.

20.The sum total of mass of an element.