Middle Grade 7 Science

Question 1

Bromine has a melting point of ​-7^{\circ}C​ and a boiling point of ​59^{\circ}C​. What is the physical state of bromine at room temperature (​21^{\circ}C​)?

Accepted Answer

2

Question 2

In a chemical reaction, a salt is formed when magnesium carbonate reacts with hydrochloric acid.

Accepted Answer

o

Question 3

An astronaut is in space with four jets producing forces on their suit. If the forces are balanced, what will happen to the astronaut?

Accepted Answer

1

Question 4

The factor that group 2 changed in their investigation regarding the time taken for a tablet to dissolve is the ___ of the water.

Accepted Answer

temperature

Question 5

Chloroplasts are specialized organelles found in both plant and animal cells that enable photosynthesis.

Accepted Answer

x

Question 6

The gas produced when magnesium carbonate reacts with hydrochloric acid is ___.

Accepted Answer

carbon dioxide

Question 7

If all forces acting on an object in space are balanced, the object will necessarily come to a complete stop.

Accepted Answer

x

Question 8

The mass of an astronaut is greater on Earth than it is on the Moon.

Accepted Answer

x

Question 9

In an investigation where different masses of salt are dissolved in water to see how the boiling point changes, the boiling point is the ___ variable.

Accepted Answer

dependent

Question 10

When a plane is flying at a constant height, the force of gravity must be balanced by the force of ___.

Accepted Answer

lift

Question 11

When magnesium carbonate is added to hydrochloric acid, the mixture fizzes. What gas is produced during this reaction?

Accepted Answer

0

Question 12

What is the melting point of pure lead based on the provided data table where the amount of tin is 0 percent?

Accepted Answer

327

Question 13

In an experiment measuring the boiling point of salt solutions, what is the independent variable?

Accepted Answer

1

Question 14

When a plane is flying at a constant height, the upward lift force and the downward weight force must be balanced.

Accepted Answer

o

Question 15

The melting point of a metal mixture remains constant regardless of the percentage of the components added.

Accepted Answer

x

Question 16

What is the name of the cell organelle that is responsible for absorbing light energy for photosynthesis?

Accepted Answer

chloroplast

Question 17

What is the physical state of bromine at room temperature given its melting point is -7 degrees Celsius and its boiling point is 59 degrees Celsius?

Accepted Answer

liquid

Question 18

How does the mass of an astronaut compare when they move from the Earth to the Moon?

Accepted Answer

0

Question 19

Group 1 investigated the factors affecting the time taken for an indigestion tablet to dissolve in water. If they found that a finely crushed tablet dissolved faster than a whole tablet, what is the most likely reason for this result?

Accepted Answer

3

Question 20

Adding more salt to water decreases the boiling point of the resulting solution.

Accepted Answer

x